Protein Info for BT2157 in Bacteroides thetaiotaomicron VPI-5482

Updated annotation (from data): 3-keto-alpha-glucoside 1,2-lyase; 3-ketoglucose dehydratase
Rationale: Important for the utilization of palatinose, D-trehalose, D-leucrose, and possibly raffinose. This gene is in a conserved cluster for disaccharide catabolism via the 3-ketoglycoside pathway. Originally proposed to be a hydrolase (PMC8121099), it is a lyase, forming 2-hydroxy-3-keto-D-glucal (PMID:38898276, PMID:37932298). It prefers 3-keto-alpha-glycoside substrates over beta substrates (PMID:38898276, PMID:37932298). At a lower rate than the lyase reaction, it hydrates 2-hydroxy-3-keto-D-glucal to 3-ketoglucose (PMID:38898276, PMID:37932298); this activity is also thought to be required for the 3-ketoglycoside pathway, as the 3-ketoglucose is converted to glucose for catabolism (see BT2159). This enzyme is probably in the periplasm.
Original annotation: conserved hypothetical protein (NCBI ptt file)

These analyses and tools can help you predict a protein's function, but be skeptical. For enzymes, over 10% of annotations from KEGG or SEED are probably incorrect. For other types of proteins, the error rates may be much higher. MetaCyc and Swiss-Prot have low error rates, but the best hits in these databases are often quite distant, so this protein's function may not be the same. TIGRFam has low error rates. Finally, many experimentally-characterized proteins are not in any of these databases. To find relevant papers, use PaperBLAST.

Protein Families and Features

• PF06439: 3keto-disac_hyd
  • amino acids 62 to 287 (226 residues), 158.2 bits, E=1.3e-50

Best Hits

KEGG orthology group: None (inferred from 100% identity to bth:BT_2157)

MetaCyc: 100% identical to 3'-ketodisaccharide hydrolase (Bacteroides thetaiotaomicron)
RXN-22812 [EC: 3.2.1.218]

Predicted SEED Role

"Probable secreted glycosyl hydrolase"

MetaCyc Pathways

• sucrose degradation VII (sucrose 3-dehydrogenase) (1/4 steps found)

Isozymes

No predicted isozymes

Use Curated BLAST to search for 3.2.1.218

Sequence Analysis Tools

See Q8A5T1 at UniProt or InterPro

Protein Sequence (290 amino acids)

>BT2157 3-keto-alpha-glucoside 1,2-lyase; 3-ketoglucose dehydratase (Bacteroides thetaiotaomicron VPI-5482)
MKKVFYPLACCLAAGVLVSCSGQKKAGSAQEEQSANEVAVSYSKSLKAAEMDSLQLPVDA
DGYITIFDGKTFNGWRGYGKDRVPSKWTIEDGCIKFNGSGGGEAQDGDGGDLIFAHKFKN
FELEMEWKVSKGGNSGIFYLAQEVTSKDKDGNDVLEPIYISAPEYQVLDNDNHPDAKLGK
DNNRQSASLYDMIPAVPQNAKPFGEWNKAKIMVYKGTVVHGQNDENVLEYHLWTKQWTDL
LQASKFSQDKWPLAFELLNNCGGENHEGFIGMQDHGDDVWFRNIRVKVLD