CG8841 (Q0E9B5) comparison with PTHR21575:SF12 HID1 proteins
Script: compare_hid1_orthologs.py (run with
uv run --no-project --with biopython --with requests python compare_hid1_orthologs.py).
Raw output: compare_hid1_orthologs.out.
Method: sequences fetched from the UniProt REST API; global pairwise alignment
(BLOSUM62, gap open -10, extend -0.5); identity is reported over aligned (non-gap)
columns, over the full CG8841 length, and over the last 150 residues of each pair.
All compared proteins are PANTHER PTHR21575:SF12 members (per
interpro/panther/PTHR21575/PTHR21575-entries.csv).
Results (copied from compare_hid1_orthologs.out)
Q0E9B5 length 837; N-terminus MGNTDSKL; Gly2=True
| Accession |
Protein |
Length |
N-terminus |
Gly2 |
Identity (aligned) |
Identity (query) |
C-terminal 150 aa identity |
| Q8IV36 |
H. sapiens HID1 |
788 |
MGSTDSKL |
yes |
68.7% |
63.3% |
72.5% |
| Q8R1F6 |
M. musculus Hid1 |
788 |
MGSADSKL |
yes |
69.7% |
63.7% |
78.0% |
| D4A0C3 |
R. norvegicus Hid1 |
788 |
MGSADSKL |
yes |
68.8% |
63.1% |
76.6% |
| Q9P7M6 |
S. pombe hid3 (SPAC17A5.16) |
797 |
MGSQQSKL |
yes |
29.9% |
26.3% |
24.6% |
| Q06673 |
S. cerevisiae ECM30 |
1274 |
MGNTDSKS |
yes |
27.5% |
24.6% |
28.0% |
Interpretation
- CG8841 is a full-length HID1 protein, about 69% identical to the mammalian HID1
proteins over aligned positions. Its extra length (837 vs 788 aa) is accounted for by
the UniProt MobiDB-lite disordered acidic segment (residues 570-705) and is not a
truncation or a missing domain.
- The N-terminal Gly2 myristoylation motif (MGxxxSKL), which is required for Golgi
membrane binding of mammalian and nematode HID-1 (PMID:21337012, PMID:21115972), is
conserved.
- The C-terminal region is conserved (72-78% identity to the mammalian C-terminal 150
residues).
- Fungal members of the same subfamily are much more distant (25-30%), consistent with
dense-core-vesicle functions being a metazoan specialization layered on the ancestral
Golgi role.
- Pairwise identity does not by itself establish orthology; the orthology claim rests on
shared PANTHER subfamily membership (SF12) and on the PAINT nodes from which the
GO_Central IBA annotations descend.