PF02643: DUF192

Uncharacterized ACR, COG1430

Curation status: SEEDED
Seed status: KNOWN HISTORICAL DUF
Characterization: UNSCORED

Grounding

PF02643: Uncharacterized ACR, COG1430
IPR003795: integrated entry for Uncharacterized ACR, COG1430

Source description

Two structures have been solved for members of this large (>500 members) family of bacterial proteins present mostly in environmental bacteria and metagenomes (distant homologues are also present in several Plasmodium species). TOPSAN analysis for pdb:3pjy shows that there is much similarity with the other solved structure, pdb:3m7a, solved for UniProt:Q2GA55 (Saro_0823), a homologue of Thermotoga maritima TM1668, UniProt:Q9X1Z6., The homologue in Caulobacter crescentus (CC1388), UniProt:Q9A8G6, is associated with CspD, a cold shock protein (CC1387), UniProt:Q9A8G7. However, the genomic context of UniProt:Q2GA55 is most conserved with a putative xylose isomerase, suggesting a possible role in extracellular sugar processing. Saro_0821, UniProt:Q2GA57, is annotated as an AMP-dependent synthetase and ligase. PDB:3m7a structure corresponds to the C-terminal (27-165) fragment of the YP_496102 (Saro_0823) protein and it is structurally unique, as the best hits from Dali have a Z-score of 3.8 (1nt0, 2j1t, 3kq4) and it is thus a likely candidate for a new fold. Interestingly, many of the top Dali hits are involved in sugar metabolism. There are no obvious active site-like cavities on the protein surface of 3m7a (http://www.topsan.org/Proteins/JCSG/).

Evidence and references

Frozen description source: InterPro/Pfam API

Source descriptions and links are provenance, not independent functional validation.

Evidence counts: not scored.

Curated functional assertions

No curated functional assertions supplied.

Protein sequence examples

4 verified sequence examples. FASTA

UniProt	Protein / organism	Sequence	Provenance
O27430	UPF0127 protein MTH_1377 Methanothermobacter thermautotrophicus (strain ATCC 29096 / DSM 1053 / JCM 10044 / NBRC 100330 / Delta H)	123 aa; version 1 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF02643
Q58891	UPF0127 protein MJ1496 Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440)	114 aa; version 2 UniProt 2026_03	PTM REGISTRY MIRROR 3 sibling references ProteinTraitsMech: InterPro:IPR038695 ProteinTraitsMech: CATH:2.60.120.1140 ProteinTraitsMech: UniProtKB:Q58891
Q8U203	UPF0127 protein PF1050 Pyrococcus furiosus (strain ATCC 43587 / DSM 3638 / JCM 8422 / Vc1)	116 aa; version 1 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF02643
Q9UZM5	UPF0127 protein PYRAB11210 Pyrococcus abyssi (strain GE5 / Orsay)	117 aa; version 1 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF02643

Pfam membership is not functional evidence. Whole-protein sequences do not establish domain boundaries. A coverage gap here is not absence from UniProt.

Sequences and metadata: UniProt Consortium, CC BY 4.0.

Domain matches

No residue-level domain match evidence is available in this build. Structure and AlphaFold counters do not supply coordinates or establish function.

Snapshot counters

proteins: 8,199
matches: 8,203
proteomes: 7,198
taxa: 10,914
structures: 2
alphafold models: 5,508
domain architectures: 19

Classification basis

short name matches duf

No scoring reasons supplied.

Related Mech records

Family	Mech	Record	Protein	Link basis
DUF192 (PF02643)	ProteinTraitsMech	Uncharacterized ACR, COG1430	O27430 UPF0127 protein MTH_1377	canonical example family classification
DUF192 (PF02643)	ProteinTraitsMech	Uncharacterized ACR, COG1430	Q8U203 UPF0127 protein PF1050	canonical example family classification
DUF192 (PF02643)	ProteinTraitsMech	Uncharacterized ACR, COG1430	Q9UZM5 UPF0127 protein PYRAB11210	canonical example family classification
DUF192 (PF02643)	ProteinTraitsMech	Uncharacterized ACR, COG1430		trait identifier
DUF192 (PF02643)	ProteinTraitsMech	Saro_0823-like superfamily	Q58891 UPF0127 protein MJ1496	canonical example family classification
DUF192 (PF02643)	ProteinTraitsMech	Protein of unknown function DUF192	Q58891 UPF0127 protein MJ1496	canonical example family classification

Curation history and reviews

No retained curation events supplied.

No retained review supplied.

Record source

data/families/PF02643.yaml
Family YAML in this build

Download this family (JSON)

Status and evidence

Seed status: A name-based classification of frozen InterPro/Pfam metadata. UNKNOWN CANDIDATE means the metadata explicitly says the function is unknown. KNOWN HISTORICAL DUF means a DUF name matched without that wording; this heuristic is not proof of a known function and does not establish experimental characterization. EX DUF means Pfam renamed the family away from a DUF/UPF name, as recorded in Pfam's previous identifiers; a rename usually follows published work on some members but is naming history, not proof of function for every member. Some EX DUF families' current names or descriptions still say the function is unknown; their classification basis lists this, and scoring does not treat them as characterized. FALSE POSITIVE TEXT HIT means the naming rules did not match.
Characterization: A separate evidence-scoring result. UNSCORED means no score has been calculated; it is not evidence that the family lacks a known function. Missing scores are not negative evidence. PARTIALLY CHARACTERIZED has partial support; KNOWN HISTORICAL DUF can inherit the seed label or reflect a known-function signal. Neither label implies experimental validation.
Evidence counts: Source-specific signals, not unique proteins, publications, or confidence scores. Known counts Rhea reactions and experimentally supported GO molecular-function annotations. Partial counts functional/domain assignments. Context counts structural, environmental, orthology, interaction and neighborhood signals; context alone does not assign function. Repeated annotations may not be independent.
Curation status: Reported separately from seed classification and characterization. SNAPSHOT ONLY means no curated metadata was supplied for this build. SEEDED denotes a source-derived record, not an expert-reviewed functional claim.
Missing counts: Not available means the source did not supply that counter. A zero is a reported count. Not scored means evidence counts are unavailable.