Tus-dependent bacterial MnmA tRNA wobble-uridine thiolation

A Tus-dependent bacterial sulfur-relay module that mobilizes sulfur from cysteine and passes it through TusA, the TusBCD complex, and TusE to MnmA, which installs 2-thiouridine at the wobble uridine of substrate tRNAs. Sulfur mobilization, carrier handoffs, complex-mediated transfer, and tRNA thiolation are modeled as separate substantive roles.

MODULE:bacterial_mnma_trna_thiolationDRAFTBiological Processmodules/bacterial_mnma_trna_thiolation.yaml
tRNA wobble position uridine thiolationGO:0002143
GO:0002143
tRNA wobble position uridine thiolation
GO:0002143 identifies the biological process performed by the bacterial Tus sulfur relay and MnmA.
file:PSEPK/iscS/iscS-uniprot.txt
PSEPK IscS UniProt record
Q88PK8 is the KT2440 cysteine desulfurase that mobilizes sulfur for tRNA modification and other sulfur-dependent pathways.
file:PSEPK/tusA/tusA-uniprot.txt
PSEPK TusA UniProt record
Q88L21 is a TusA-family sulfur carrier assigned to U34 thiolation.
file:PSEPK/tusD/tusD-uniprot.txt
PSEPK TusD UniProt record
Q88FT9 is the TusD sulfur-carrying subunit of the TusBCD complex.
file:PSEPK/PP_3994/PP_3994-uniprot.txt
PSEPK TusC-like UniProt record
Q88FT8 is a TusC-family subunit encoded in the KT2440 tusBCDE locus.
file:PSEPK/PP_3995/PP_3995-uniprot.txt
PSEPK TusB UniProt record
Q88FT7 is a TusB-family subunit encoded in the KT2440 tusBCDE locus.
file:PSEPK/tusE/tusE-uniprot.txt
PSEPK TusE UniProt record
Q88FT6 is a TusE-family sulfur carrier in the relay.
file:PSEPK/mnmA/mnmA-uniprot.txt
PSEPK MnmA UniProt record
Q88FR9 catalyzes ATP-dependent 2-thiolation of wobble uridine in tRNA.
PMID:16387657
Mechanistic insights into sulfur relay by multiple sulfur mediators involved in thiouridine biosynthesis at tRNA wobble positions.
Biochemical reconstitution established the ordered IscS-TusA-TusBCD-TusE- MnmA relay in E. coli.
PMID:16472754
Structural basis for sulfur relay to RNA mediated by heterohexameric TusBCD complex.
Structure and mutagenesis established heterohexameric TusBCD and the sulfur-transfer role of TusD Cys78.

This module represents the Tus-dependent implementation of the MnmA pathway; it is not asserted to be universal across bacteria. IscS also supplies sulfur to iron-sulfur cluster and cofactor pathways; those branches are outside this boundary. MnmC-dependent elaboration of the modified uridine is downstream and is likewise excluded. The exact KT2440 gene names for Q88FT8, Q88FT7, and Q88FT6 remain locus-tag based in the review files, while their family roles are represented as TusC, TusB, and TusE here.

6Nodes
5Parts
0Variant Sets
0Variants
7Annotons
4Connections

Derived QC

Recommended-field compliance

60.0% recommended fields populated
  • module.knowledge_gaps[0] · status (0/1)
  • module.knowledge_gaps[0] · provenance (0/1)

Module deep research

✗ none found

No MODULE:bacterial_mnma_trna_thiolation deep-research report alongside the module YAML.

Leaf nodes lacking representative members

✓ every leaf node grounds to a representative protein.

Template conformance

✓ every declared conforms_to bundle matches its template motif.

Gene-review completeness (7/7 grounded genes reviewed)

7 complete review(s) · 0 with deep research · 0 missing review · 7 reviewed but lacking deep research

Gene Review Complete Deep research
iscS Q88PK8 ✓ ✓ ✗
mnmA Q88FR9 ✓ ✓ ✗
PP_3994 Q88FT8 ✓ ✓ ✗
PP_3995 Q88FT7 ✓ ✓ ✗
tusA Q88L21 ✓ ✓ ✗
tusD Q88FT9 ✓ ✓ ✗
tusE Q88FT6 ✓ ✓ ✗

Details

Context
GammaproteobacteriaNCBITaxon:1236
Tus-dependent bacterial MnmA tRNA wobble-uridine thiolationBiological Processbacterial_mnma_trna_thiolation
tRNA wobble position uridine thiolationGO:0002143
Context
GammaproteobacteriaNCBITaxon:1236

Connections

Part 1: Sulfur mobilization from cysteine
IscS sulfur mobilizationReactioniscs_sulfur_mobilization

A cysteine desulfurase generates enzyme-bound persulfide sulfur that enters the Tus relay.

Annotons

IscS-family cysteine desulfurase
iscs_cysteine_desulfurase
Participant: Family: IscS family
Family:
IscS familyInterPro:IPR010240
Representative Members: PSEPK IscS exemplarUniProtKB:Q88PK8

Function

cysteine desulfurase activityGO:0031071

Processes

tRNA wobble position uridine thiolationGO:0002143

Mobilizes sulfur from cysteine for entry into the relay.

Part 2: Initial sulfur-carrier handoff
TusA sulfur handoffReactiontusa_sulfur_handoff

TusA receives mobilized sulfur and transfers it to TusBCD.

Annotons

TusA-family sulfur carrier
tusa_sulfur_carrier
Participant: Family: TusA family
Family:
TusA familyInterPro:IPR022931
Representative Members: PSEPK TusA exemplarUniProtKB:Q88L21

Function

sulfur carrier activityGO:0097163

Processes

tRNA wobble position uridine thiolationGO:0002143

Carries sulfur from IscS to the TusBCD complex.

Part 3: TusBCD complex-mediated sulfur transfer
TusBCD sulfur-transfer complexProtein Complextusbcd_sulfur_transfer

TusB, TusC, and TusD form a heterohexameric sulfur-transfer complex; TusD carries the transferable sulfur while all three subunits are required for the organized relay.

sulfurtransferase complexGO:1990228

Annotons

TusD sulfur-carrying subunit
tusd_sulfur_carrier
Participant: Family: TusD family
Family:
TusD familyPANTHER:PTHR34874
Representative Members: PSEPK TusD exemplarUniProtKB:Q88FT9

Function

sulfur carrier activityGO:0097163

Processes

tRNA wobble position uridine thiolationGO:0002143

Sulfur-bearing TusBCD subunit.

TusC complex subunit
tusc_complex_subunit
Participant: Family: TusC family
Family:
TusC familyPANTHER:PTHR38780
Representative Members: PSEPK TusC exemplarUniProtKB:Q88FT8

Processes

tRNA wobble position uridine thiolationGO:0002143

Structural TusBCD subunit required for relay-complex assembly.

TusB complex subunit
tusb_complex_subunit
Participant: Family: TusB family
Family:
TusB familyPANTHER:PTHR37526
Representative Members: PSEPK TusB exemplarUniProtKB:Q88FT7

Processes

tRNA wobble position uridine thiolationGO:0002143

Structural TusBCD subunit required for relay-complex assembly.

Part 4: Terminal sulfur-carrier handoff
TusE terminal sulfur handoffReactiontuse_terminal_handoff

TusE carries sulfur from TusBCD to MnmA.

Annotons

TusE-family sulfur carrier
tuse_sulfur_carrier
Participant: Family: TusE family
Family:
TusE familyPANTHER:PTHR37010
Representative Members: PSEPK TusE exemplarUniProtKB:Q88FT6

Function

sulfur carrier activityGO:0097163

Processes

tRNA wobble position uridine thiolationGO:0002143

Terminal soluble sulfur carrier that supplies MnmA.

Part 5: ATP-dependent tRNA U34 thiolation
MnmA-catalyzed tRNA U34 thiolationReactionmnma_trna_thiolation

MnmA activates wobble uridine using ATP and incorporates relay-derived sulfur to form 2-thiouridine.

Annotons

MnmA tRNA-uridine 2-sulfurtransferase
mnma_trna_uridine_sulfurtransferase
Participant: Family: MnmA family
Family:
MnmA familyInterPro:IPR004506
Representative Members: PSEPK MnmA exemplarUniProtKB:Q88FR9

Function

tRNA-uridine 2-sulfurtransferase activityGO:0103016

Processes

tRNA wobble position uridine thiolationGO:0002143

Catalyzes the terminal ATP-dependent tRNA thiolation reaction.