bcsA encodes the multi-pass inner-membrane catalytic subunit of bacterial cellulose synthase, a GT2 enzyme that polymerizes UDP-glucose into cellulose during cellulose biosynthesis.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005886 plasma membrane | IEA GO_REF:0000120 | ACCEPT | Summary: Plasma membrane is the appropriate bacterial inner-membrane location for BcsA. Reason: UniProt places BcsA in the cell inner membrane and records it as a multi-pass membrane protein. Supporting Evidence: file:PSEPK/bcsA/bcsA-uniprot.txt SUBCELLULAR LOCATION: Cell inner membrane file:PSEPK/bcsA/bcsA-goa.tsv GO:0005886 plasma membrane |
| GO:0006011 UDP-alpha-D-glucose metabolic process | IEA GO_REF:0000002 | MODIFY | Summary: UDP-alpha-D-glucose metabolism is related to the donor substrate but is not the best process term for BcsA. Reason: BcsA uses UDP-glucose as the donor for cellulose polymerization, so the pathway-level annotation should be cellulose biosynthetic process rather than the broad donor-substrate metabolic process. Proposed replacements: cellulose biosynthetic process Supporting Evidence: file:PSEPK/bcsA/bcsA-uniprot.txt PATHWAY: Glycan metabolism; bacterial cellulose biosynthesis. file:PSEPK/bcsA/bcsA-goa.tsv GO:0006011 UDP-alpha-D-glucose metabolic process |
| GO:0016020 membrane | IEA GO_REF:0000002 | MODIFY | Summary: Membrane is correct but less specific than the bacterial plasma membrane assignment already present. Reason: BcsA is specifically an inner-membrane multi-pass protein; GO:0005886 is the more informative cellular-component term. Proposed replacements: plasma membrane Supporting Evidence: file:PSEPK/bcsA/bcsA-uniprot.txt SUBCELLULAR LOCATION: Cell inner membrane file:PSEPK/bcsA/bcsA-goa.tsv GO:0016020 membrane |
| GO:0016758 hexosyltransferase activity | IEA GO_REF:0000118 | MODIFY | Summary: Hexosyltransferase activity is correct but too broad for the BcsA catalytic subunit. Reason: UniProt and GOA assign the specific UDP-forming cellulose synthase activity, which is more informative than the generic hexosyltransferase parent. Proposed replacements: cellulose synthase (UDP-forming) activity Supporting Evidence: file:PSEPK/bcsA/bcsA-uniprot.txt FUNCTION: Catalytic subunit of cellulose synthase file:PSEPK/bcsA/bcsA-goa.tsv GO:0016758 hexosyltransferase activity |
| GO:0016759 cellulose synthase activity | IEA GO_REF:0000002 | MODIFY | Summary: Cellulose synthase activity is correct but should be made specific to the UDP-forming activity. Reason: The BcsA reaction is explicitly Rhea/EC-mapped as cellulose synthase (UDP-forming) activity, so GO:0016760 is the preferred specific term. Proposed replacements: cellulose synthase (UDP-forming) activity Supporting Evidence: file:PSEPK/bcsA/bcsA-uniprot.txt Reaction=[(1->4)-beta-D-glucosyl](n) + UDP-alpha-D-glucose file:PSEPK/bcsA/bcsA-goa.tsv GO:0016759 cellulose synthase activity |
| GO:0016760 cellulose synthase (UDP-forming) activity | IEA GO_REF:0000120 | ACCEPT | Summary: The UDP-forming cellulose synthase activity is the core catalytic function of BcsA. Reason: UniProt describes BcsA as the catalytic subunit of cellulose synthase, maps EC 2.4.1.12/Rhea:19929, and GOA already contains the specific UDP-forming cellulose synthase term. Supporting Evidence: file:PSEPK/bcsA/bcsA-uniprot.txt FUNCTION: Catalytic subunit of cellulose synthase file:PSEPK/bcsA/bcsA-uniprot.txt EC=2.4.1.12 PMID:23222542 The inner membrane protein BcsA is the catalytically active subunit and contains a conserved family two GT-domain between TM-helices 4 and 5 file:PSEPK/bcsA/bcsA-goa.tsv GO:0016760 cellulose synthase (UDP-forming) activity |
| GO:0035438 cyclic-di-GMP binding | IEA GO_REF:0000002 | KEEP AS NON CORE | Summary: Cyclic-di-GMP binding is a relevant regulatory activity for BcsA but is secondary to the catalytic cellulose synthase function. Reason: BcsA-family cellulose synthases are c-di-GMP regulated, and InterPro/UniProt support cyclic-di-GMP binding; the core catalytic output remains cellulose synthase activity. Supporting Evidence: file:PSEPK/bcsA/bcsA-goa.tsv GO:0035438 cyclic-di-GMP binding file:PSEPK/bcsA/bcsA-uniprot.txt Catalytic subunit of cellulose synthase PMID:24704788 BcsA forms a PilZ domain within its C-terminal intracellular extension |
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Download this section (compressed HTML)Q: Does KT2440 BcsA produce extracellular cellulose under the tested low-nutrient or biofilm conditions, and which c-di-GMP signals activate it?
Q: Which neighboring bcs-locus proteins are required with BcsA for cellulose export and mature polymer assembly?
Experiment: Assay cellulose production in wild-type and bcsA deletion strains using calcofluor/Congo red staining and beta-1,4-glucan quantification under biofilm-inducing conditions.
Type: targeted genetics and polysaccharide profiling
Experiment: Reconstitute BcsA/BcsB membrane complexes with UDP-glucose and c-di-GMP to measure cellulose synthase activity.
Type: in vitro glycosyltransferase assay
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