View original ARBA rule on UniProt
TODO: Provide a concise description of what this rule predicts and how
Condition-set counts describe the sets recorded in this review, which may omit the full rule.
Interactive prediction matrix showing how row entries PREDICT column entries. Cell (i,j) shows what fraction of proteins with row domain i also have column domain j. Click cells to view intersection in UniProt. Click domain IDs to view proteins with that domain.
Legend: Each cell shows PREDICTS % (fraction of row entry proteins that also have column entry - row PREDICTS column), Jaccard similarity (J:%), and intersection count. CS = Condition Set(s), TGT = GO annotation target.
ARBA00004841 attempts to identify key enzymes in heparin/heparan sulfate biosynthesis but has significant limitations. The rule correctly targets NDST (N-deacetylase/N-sulfotransferase) and GLCE (glucuronyl C5-epimerase) enzymes, which are essential for HS biosynthesis. However, the implementation is problematic: condition set 1 includes the overly broad P-loop domain (IPR027417) affecting 40,360 proteins, creating substantial false positive risk. Condition set 2 contains completely redundant domains (IPR010598≡IPR039721). Most critically, the rule provides only pathway annotation without GO terms, severely limiting its utility. While the biological foundation is sound and condition set 3 shows good specificity through CATH FunFam classification, the rule requires significant modifications to be useful for accurate protein annotation.
Rule captures biologically relevant enzymes but suffers from major design flaws: (1) lacks GO term annotations, (2) includes overly broad P-loop domain creating false positive risk, (3) contains redundant C5-epimerase domains, and (4) misses other essential biosynthetic enzymes. Core biological basis is sound but implementation needs significant refinement.
Rule contains significant redundancy and unnecessary complexity. Condition set 2 has completely redundant domains (IPR010598≡IPR039721, Jaccard=1.0) and near-redundant domains (IPR059154, Jaccard=0.833). Condition set 1 includes overly broad P-loop domain that adds no specificity but increases false positive risk. Only condition set 3 shows appropriate parsimony with specific CATH FunFam classification.
Strong literature support for the biological relevance of targeted enzymes in heparin/heparan sulfate biosynthesis. NDST enzymes are well-characterized bifunctional enzymes, and GLCE is the essential C5-epimerase. However, literature also reveals the rule misses other critical enzymes in the pathway.
Analysis reveals major overlap issues: condition set 2 contains completely redundant domains (IPR010598≡IPR039721, Jaccard=1.0) and highly overlapping domains (IPR059154, Jaccard=0.833). Condition set 1 shows subset relationships where IPR021930⊆IPR000863⊆IPR027417, with the broadest domain creating false positive risk. Cross-condition analysis shows appropriate separation between NDST-related (set 1,3) and GLCE-related (set 2) functions.
Rule lacks GO term annotations entirely, providing only pathway annotation ("Glycan metabolism; heparin biosynthesis"). This is a critical limitation as GO terms are essential for functional annotation. The pathway annotation is appropriate but insufficient for modern annotation standards.
Eukaryotic restriction in condition set 3 is biologically justified. The complex heparin/heparan sulfate biosynthesis pathway with bifunctional NDST enzymes is specific to eukaryotes. Prokaryotes lack this sophisticated glycosaminoglycan modification system.
NDST enzymes are bifunctional with both N-deacetylase and N-sulfotransferase activities, essential for heparin biosynthesis
GLCE (glucuronyl C5-epimerase) converts glucuronic acid to iduronic acid, critical for chain flexibility and subsequent sulfation
IPR027417 (P-loop domain) is overly broad, affecting 40,360 proteins including many unrelated ATP-binding enzymes
Condition set 2 contains redundant domains with IPR010598≡IPR039721 (Jaccard=1.0)
Rule lacks GO term annotations, providing only pathway annotation which is insufficient for modern standards
id: ARBA00004841
description: 'TODO: Provide a concise description of what this rule predicts and how'
status: IN_PROGRESS
rule_type: ARBA
rule:
rule_id: ARBA00004841
condition_sets:
- number: 1
conditions:
- condition_type: INTERPRO
value: IPR000863
curie: InterPro:IPR000863
label: Sulfotransferase domain
negated: false
- condition_type: INTERPRO
value: IPR021930
curie: InterPro:IPR021930
label: Heparan sulphate-N-deacetylase, deacetylase domain
negated: false
- condition_type: INTERPRO
value: IPR027417
curie: InterPro:IPR027417
label: P-loop containing nucleoside triphosphate hydrolase
negated: false
notes: ''
pairwise_overlap:
- condition_a: IPR000863
condition_b: IPR021930
protein_database: SWISSPROT
count_a: 152
count_b: 15
intersection_count: 15
a_minus_b_count: 137
b_minus_a_count: 0
jaccard_similarity: 0.09868421052631579
containment_a_in_b: 0.09868421052631579
containment_b_in_a: 1.0
interpretation: SUBSET
- condition_a: IPR000863
condition_b: IPR027417
protein_database: SWISSPROT
count_a: 152
count_b: 40360
intersection_count: 152
a_minus_b_count: 0
b_minus_a_count: 40208
jaccard_similarity: 0.0037661050545094153
containment_a_in_b: 1.0
containment_b_in_a: 0.0037661050545094153
interpretation: SUBSET
- condition_a: IPR021930
condition_b: IPR027417
protein_database: SWISSPROT
count_a: 15
count_b: 40360
intersection_count: 15
a_minus_b_count: 0
b_minus_a_count: 40345
jaccard_similarity: 0.00037165510406342913
containment_a_in_b: 1.0
containment_b_in_a: 0.00037165510406342913
interpretation: SUBSET
- number: 2
conditions:
- condition_type: INTERPRO
value: IPR010598
curie: InterPro:IPR010598
label: D-glucuronyl C5-epimerase, C-terminal
negated: false
- condition_type: INTERPRO
value: IPR039721
curie: InterPro:IPR039721
label: D-glucuronyl C5-epimerase
negated: false
- condition_type: INTERPRO
value: IPR059154
curie: InterPro:IPR059154
label: D-glucuronyl C5-epimerase, beta-sandwich domain
negated: false
notes: ''
pairwise_overlap:
- condition_a: IPR010598
condition_b: IPR039721
protein_database: SWISSPROT
count_a: 6
count_b: 6
intersection_count: 6
a_minus_b_count: 0
b_minus_a_count: 0
jaccard_similarity: 1.0
containment_a_in_b: 1.0
containment_b_in_a: 1.0
interpretation: REDUNDANT
- condition_a: IPR010598
condition_b: IPR059154
protein_database: SWISSPROT
count_a: 6
count_b: 5
intersection_count: 5
a_minus_b_count: 1
b_minus_a_count: 0
jaccard_similarity: 0.8333333333333334
containment_a_in_b: 0.8333333333333334
containment_b_in_a: 1.0
interpretation: SUBSET
- condition_a: IPR039721
condition_b: IPR059154
protein_database: SWISSPROT
count_a: 6
count_b: 5
intersection_count: 5
a_minus_b_count: 1
b_minus_a_count: 0
jaccard_similarity: 0.8333333333333334
containment_a_in_b: 0.8333333333333334
containment_b_in_a: 1.0
interpretation: SUBSET
- number: 3
conditions:
- condition_type: FUNFAM
value: 3.40.50.300:FF:000176
curie: CATH.FunFam:3.40.50.300:FF:000176
label: bifunctional heparan sulfate N-deacetylase/N-sulfotransferase 1
negated: false
- condition_type: TAXON
value: Eukaryota
curie: NCBITaxon:2759
label: Eukaryota
negated: false
notes: ''
go_annotations: []
reviewed_protein_count: 0
unreviewed_protein_count: 0
created_date: ''
modified_date: ''
entries:
- id: 3.40.50.300:FF:000176
type: FUNFAM
label: bifunctional heparan sulfate N-deacetylase/N-sulfotransferase 1
appears_in_condition_sets:
- 3
protein_count: 13
related_entries:
- relationship: PREDICTS
target_id: IPR000863
containment: 0.086
jaccard_similarity: 0.086
intersection_count: 13
exclusive_count: 139
- relationship: PREDICTS
target_id: IPR021930
containment: 0.867
jaccard_similarity: 0.867
intersection_count: 13
exclusive_count: 2
- relationship: PREDICTS
target_id: IPR027417
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 13
exclusive_count: 40347
- relationship: EQUIV
target_id: IPR010598
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 13
- relationship: EQUIV
target_id: IPR039721
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 13
- relationship: EQUIV
target_id: IPR059154
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 13
- id: IPR000863
type: INTERPRO
label: Sulfotransferase domain
appears_in_condition_sets:
- 1
protein_count: 152
related_entries:
- relationship: PREDICTED_BY
target_id: IPR021930
containment: 1.0
jaccard_similarity: 0.099
intersection_count: 15
exclusive_count: 0
- relationship: PREDICTS
target_id: IPR027417
containment: 1.0
jaccard_similarity: 0.004
intersection_count: 152
exclusive_count: 0
- relationship: EQUIV
target_id: IPR010598
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 152
- relationship: EQUIV
target_id: IPR039721
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 152
- relationship: EQUIV
target_id: IPR059154
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 152
- relationship: PREDICTED_BY
target_id: 3.40.50.300:FF:000176
containment: 1.0
jaccard_similarity: 0.086
intersection_count: 13
exclusive_count: 0
- id: IPR010598
type: INTERPRO
label: D-glucuronyl C5-epimerase, C-terminal
appears_in_condition_sets:
- 2
protein_count: 6
related_entries:
- relationship: EQUIV
target_id: IPR000863
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 6
- relationship: EQUIV
target_id: IPR021930
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 6
- relationship: EQUIV
target_id: IPR027417
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 6
- relationship: EQUIV
target_id: IPR039721
containment: 1.0
jaccard_similarity: 1.0
intersection_count: 6
exclusive_count: 0
- relationship: PREDICTED_BY
target_id: IPR059154
containment: 1.0
jaccard_similarity: 0.833
intersection_count: 5
exclusive_count: 0
- relationship: EQUIV
target_id: 3.40.50.300:FF:000176
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 6
- id: IPR021930
type: INTERPRO
label: Heparan sulphate-N-deacetylase, deacetylase domain
appears_in_condition_sets:
- 1
protein_count: 15
related_entries:
- relationship: PREDICTS
target_id: IPR000863
containment: 0.099
jaccard_similarity: 0.099
intersection_count: 15
exclusive_count: 137
- relationship: PREDICTS
target_id: IPR027417
containment: 1.0
jaccard_similarity: 0.0
intersection_count: 15
exclusive_count: 0
- relationship: EQUIV
target_id: IPR010598
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 15
- relationship: EQUIV
target_id: IPR039721
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 15
- relationship: EQUIV
target_id: IPR059154
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 15
- relationship: PREDICTED_BY
target_id: 3.40.50.300:FF:000176
containment: 1.0
jaccard_similarity: 0.867
intersection_count: 13
exclusive_count: 0
- id: IPR027417
type: INTERPRO
label: P-loop containing nucleoside triphosphate hydrolase
appears_in_condition_sets:
- 1
protein_count: 40360
related_entries:
- relationship: PREDICTED_BY
target_id: IPR000863
containment: 0.004
jaccard_similarity: 0.004
intersection_count: 152
exclusive_count: 40208
- relationship: PREDICTED_BY
target_id: IPR021930
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 15
exclusive_count: 40345
- relationship: EQUIV
target_id: IPR010598
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 40360
- relationship: EQUIV
target_id: IPR039721
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 40360
- relationship: EQUIV
target_id: IPR059154
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 40360
- relationship: PREDICTED_BY
target_id: 3.40.50.300:FF:000176
containment: 1.0
jaccard_similarity: 0.0
intersection_count: 13
exclusive_count: 0
- id: IPR039721
type: INTERPRO
label: D-glucuronyl C5-epimerase
appears_in_condition_sets:
- 2
protein_count: 6
related_entries:
- relationship: EQUIV
target_id: IPR000863
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 6
- relationship: EQUIV
target_id: IPR021930
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 6
- relationship: EQUIV
target_id: IPR027417
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 6
- relationship: EQUIV
target_id: IPR010598
containment: 1.0
jaccard_similarity: 1.0
intersection_count: 6
exclusive_count: 0
- relationship: PREDICTED_BY
target_id: IPR059154
containment: 1.0
jaccard_similarity: 0.833
intersection_count: 5
exclusive_count: 0
- relationship: EQUIV
target_id: 3.40.50.300:FF:000176
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 6
- id: IPR059154
type: INTERPRO
label: D-glucuronyl C5-epimerase, beta-sandwich domain
appears_in_condition_sets:
- 2
protein_count: 5
related_entries:
- relationship: EQUIV
target_id: IPR000863
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 5
- relationship: EQUIV
target_id: IPR021930
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 5
- relationship: EQUIV
target_id: IPR027417
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 5
- relationship: PREDICTS
target_id: IPR010598
containment: 0.833
jaccard_similarity: 0.833
intersection_count: 5
exclusive_count: 1
- relationship: PREDICTS
target_id: IPR039721
containment: 0.833
jaccard_similarity: 0.833
intersection_count: 5
exclusive_count: 1
- relationship: EQUIV
target_id: 3.40.50.300:FF:000176
containment: 0.0
jaccard_similarity: 0.0
intersection_count: 0
exclusive_count: 5
review_summary: 'ARBA00004841 attempts to identify key enzymes in heparin/heparan sulfate biosynthesis but has significant limitations. The rule correctly targets NDST (N-deacetylase/N-sulfotransferase) and GLCE (glucuronyl C5-epimerase) enzymes, which are essential for HS biosynthesis. However, the implementation is problematic: condition set 1 includes the overly broad P-loop domain (IPR027417) affecting 40,360 proteins, creating substantial false positive risk. Condition set 2 contains completely redundant domains (IPR010598≡IPR039721). Most critically, the rule provides only pathway annotation without GO terms, severely limiting its utility. While the biological foundation is sound and condition set 3 shows good specificity through CATH FunFam classification, the rule requires significant modifications to be useful for accurate protein annotation.'
action: MODIFY
action_rationale: 'Rule captures biologically relevant enzymes but suffers from major design flaws: (1) lacks GO term annotations, (2) includes overly broad P-loop domain creating false positive risk, (3) contains redundant C5-epimerase domains, and (4) misses other essential biosynthetic enzymes. Core biological basis is sound but implementation needs significant refinement.'
suggested_modifications:
- 'Remove IPR027417 (P-loop nucleoside triphosphate hydrolase) from condition set 1 to eliminate false positives from unrelated ATP-binding proteins'
- 'Add appropriate GO terms: GO:0008467 (N-acetylglucosaminyltransferase activity), GO:0008146 (sulfotransferase activity), GO:0015020 (glucuronosyltransferase activity), GO:0015012 (heparan sulfate proteoglycan biosynthetic process)'
- 'Simplify condition set 2 by removing redundant domains IPR010598 and IPR039721 (Jaccard=1.0), keeping only IPR059154'
- 'Consider expanding to include other essential HS biosynthesis enzymes (O-sulfotransferases)'
parsimony:
assessment: REDUNDANT
notes: 'Rule contains significant redundancy and unnecessary complexity. Condition set 2 has completely redundant domains (IPR010598≡IPR039721, Jaccard=1.0) and near-redundant domains (IPR059154, Jaccard=0.833). Condition set 1 includes overly broad P-loop domain that adds no specificity but increases false positive risk. Only condition set 3 shows appropriate parsimony with specific CATH FunFam classification.'
literature_support:
assessment: STRONG
notes: 'Strong literature support for the biological relevance of targeted enzymes in heparin/heparan sulfate biosynthesis. NDST enzymes are well-characterized bifunctional enzymes, and GLCE is the essential C5-epimerase. However, literature also reveals the rule misses other critical enzymes in the pathway.'
supported_by:
- reference_id: file:rules/arba/ARBA00004841/ARBA00004841-deep-research-manual.md
supporting_text: 'Duncan et al. (1999) characterized NDST1 structure and function; Crawford et al. (2001) identified GLCE as the critical C5-epimerase; Esko & Selleck (2002) comprehensive review of HS biosynthesis pathway shows these are core enzymes but not the complete set.'
condition_overlap:
assessment: SIGNIFICANT
notes: 'Analysis reveals major overlap issues: condition set 2 contains completely redundant domains (IPR010598≡IPR039721, Jaccard=1.0) and highly overlapping domains (IPR059154, Jaccard=0.833). Condition set 1 shows subset relationships where IPR021930⊆IPR000863⊆IPR027417, with the broadest domain creating false positive risk. Cross-condition analysis shows appropriate separation between NDST-related (set 1,3) and GLCE-related (set 2) functions.'
supported_by:
- reference_id: file:rules/arba/ARBA00004841/ARBA00004841-analysis.txt
supporting_text: 'IPR010598 ↔ IPR039721: Jaccard similarity: 1.000, Interpretation: REDUNDANT; IPR010598 ↔ IPR059154: Jaccard similarity: 0.833, Interpretation: SUBSET; IPR027417 contains 40,360 proteins with only 152 overlap with sulfotransferase domain.'
go_specificity:
assessment: MISMATCHED
notes: 'Rule lacks GO term annotations entirely, providing only pathway annotation ("Glycan metabolism; heparin biosynthesis"). This is a critical limitation as GO terms are essential for functional annotation. The pathway annotation is appropriate but insufficient for modern annotation standards.'
supported_by:
- reference_id: file:rules/arba/ARBA00004841/ARBA00004841.enriched.json
supporting_text: 'mainRule.annotations contains only commentType: PATHWAY with value: Glycan metabolism; heparin biosynthesis. No GO term annotations present in the annotations array.'
taxonomic_scope:
assessment: APPROPRIATE
notes: 'Eukaryotic restriction in condition set 3 is biologically justified. The complex heparin/heparan sulfate biosynthesis pathway with bifunctional NDST enzymes is specific to eukaryotes. Prokaryotes lack this sophisticated glycosaminoglycan modification system.'
supported_by:
- reference_id: file:rules/arba/ARBA00004841/ARBA00004841-deep-research-manual.md
supporting_text: 'Eukaryotic restriction: Appropriate as this pathway architecture is eukaryote-specific. Carlsson et al. (2008) showed evolutionary conservation across vertebrates but absence in prokaryotes.'
confidence: 0.3
references:
- id: file:rules/arba/ARBA00004841/ARBA00004841-deep-research-manual.md
title: Manual deep research analysis
findings:
- statement: 'NDST enzymes are bifunctional with both N-deacetylase and N-sulfotransferase activities, essential for heparin biosynthesis'
- statement: 'GLCE (glucuronyl C5-epimerase) converts glucuronic acid to iduronic acid, critical for chain flexibility and subsequent sulfation'
- statement: 'IPR027417 (P-loop domain) is overly broad, affecting 40,360 proteins including many unrelated ATP-binding enzymes'
- statement: 'Condition set 2 contains redundant domains with IPR010598≡IPR039721 (Jaccard=1.0)'
- statement: 'Rule lacks GO term annotations, providing only pathway annotation which is insufficient for modern standards'
supported_by:
- reference_id: file:rules/arba/ARBA00004841/ARBA00004841-analysis.yaml
supporting_text: 'Domain overlap analysis shows significant redundancy in condition set 2 and overly broad domains in condition set 1'
- reference_id: file:rules/arba/ARBA00004841/ARBA00004841-deep-research-manual.md
supporting_text: 'Comprehensive analysis of heparin biosynthesis pathway and enzyme specificities supports biological relevance but reveals implementation flaws'