BetaGal_dom2 Beta-galactosidase, domain 2
SMART ACC:	SM001029
Description:	This is the second domain of the five-domain beta-galactosidase enzyme that altogether catalyses the hydrolysis of beta(1-3) and beta(1-4) galactosyl bonds in oligosaccharides as well as the inverse reaction of enzymatic condensation and trans-glycosylation. This domain is made up of 16 antiparallel beta-strands and an alpha-helix at its C terminus. The fold of this domain appears to be unique. In addition, the last seven strands of the domain form a subdomain with an immunoglobulin-like (I-type Ig) fold in which the first strand is divided between the two beta-sheets. In penicillin spp this strand is interrupted by a 12-residue insertion which forms an additional edge-strand to the second beta-sheet of the sub-domain. The remainder of the second domain forms a series of beta-hairpins at its N terminus, four strands of which are contiguous with part of the Ig-like sub-domain, forming in total a seven-stranded antiparallel beta-sheet. This domain is associated with family Glyco_hydro_35, which is N-terminal to it, but itself has no metazoan members.
InterPro ACC:	IPR018954
InterPro abstract:	This entry represents the second domain of the five-domain beta-galactosidase enzyme that altogether catalyses the hydrolysis of beta(1-3) and beta(1-4) galactosyl bonds in oligosaccharides as well as the inverse reaction of enzymatic condensation and trans-glycosylation. This domain is made up of 16 antiparallel β-strands and an α-helix at its C terminus. The fold of this domain appears to be … expand This entry represents the second domain of the five-domain beta-galactosidase enzyme that altogether catalyses the hydrolysis of beta(1-3) and beta(1-4) galactosyl bonds in oligosaccharides as well as the inverse reaction of enzymatic condensation and trans-glycosylation. This domain is made up of 16 antiparallel β-strands and an α-helix at its C terminus. The fold of this domain appears to be unique. In addition, the last seven strands of the domain form a subdomain with an immunoglobulin-like (I-type Ig) fold in which the first strand is divided between the two β-sheets. In penicillin spp this strand is interrupted by a 12-residue insertion which forms an additional edge-strand to the second β-sheet of the sub-domain. The remainder of the second domain forms a series of β-hairpins at its N terminus, four strands of which are contiguous with part of the Ig-like sub-domain, forming in total a seven-stranded antiparallel β-sheet. collapse
Family alignment:	View the Family alignment or the Alignment consensus sequence
There are 354 BetaGal_dom2 domains in 353 proteins in SMART's NRDB database.

Taxonomic distribution of proteins containing BetaGal_dom2 domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing BetaGal_dom2 domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

Relevant references for this domain

Primary literature for the BetaGal_dom2 domain is listed below. Automatically-derived, secondary literature is also available.

KEGG pathways involving proteins which contain this domain

This information is based on the mapping of SMART genomic protein database to KEGG orthologous groups. Percentages are related to the number of proteins containing a BetaGal_dom2 domain which could be assigned to a KEGG orthologous group, and not all proteins containing BetaGal_dom2 domains. Please note that proteins can be included in multiple pathways, ie. the numbers below will not add to 100%.

KEGG pathways

Some of these pathways are included in the interactive Pathways Explorer overview maps. Select an overview map and click the button below to highlight them in iPath.

KEGG orthologous groups

Some of these KOs are included in the interactive Pathways Explorer overview maps. Select an overview map and click the button below to highlight them in iPath.

3D structures in PDB containing this domain

Links to other resources describing this domain

InterPro	IPR018954
Pfam	BetaGal_dom2