9vak

Structural highlights

Function

LNBB_BIFB1 Present in the infant gut, this enzyme is involved in the assimilation of type-1 human milk oligosaccharides (HMOs). It hydrolyzes via a retaining mechanism the beta-D-GlcNAc-(1->3)-beta-D-Gal linkage in lacto-N-tetraose (LNT or beta-D-Gal-(1->3)-beta-D-GlcNAc-(1->3)-beta-D-Gal-(1->4)-D-Glc), an abundant HMO unique to human breast milk, releasing lacto-N-biose (LNB or beta-D-Gal-(1->3)-D-GlcNAc) and lactose (PubMed:18469123, PubMed:23479733). Is a key enzymatic factor for growth and proliferation of B.bifidum in the gut ecosystem of breast-fed infants (Probable). Has substrate preference for unmodified beta-linked LNB since it does not hydrolyze the fucosylated forms of lacto-N-tetraose (lacto-N-fucopentaose I and II) or lacto-N-neotetraose. Is also able to display transglycosylation activity in vitro (PubMed:18469123).^{[1] [2] [3]}

References

1. ↑ Wada J, Ando T, Kiyohara M, Ashida H, Kitaoka M, Yamaguchi M, Kumagai H, Katayama T, Yamamoto K. Bifidobacterium bifidum lacto-N-biosidase, a critical enzyme for the degradation of human milk oligosaccharides with a type 1 structure. Appl Environ Microbiol. 2008 Jul;74(13):3996-4004. doi: 10.1128/AEM.00149-08., Epub 2008 May 9. PMID:18469123 doi:http://dx.doi.org/10.1128/AEM.00149-08
2. ↑ Ito T, Katayama T, Hattie M, Sakurama H, Wada J, Suzuki R, Ashida H, Wakagi T, Yamamoto K, Stubbs KA, Fushinobu S. Crystal structures of a glycoside hydrolase family 20 lacto-N-biosidase from Bifidobacterium bifidum. J Biol Chem. 2013 Apr 26;288(17):11795-806. doi: 10.1074/jbc.M112.420109. Epub, 2013 Mar 11. PMID:23479733 doi:10.1074/jbc.M112.420109
3. ↑ Ito T, Katayama T, Hattie M, Sakurama H, Wada J, Suzuki R, Ashida H, Wakagi T, Yamamoto K, Stubbs KA, Fushinobu S. Crystal structures of a glycoside hydrolase family 20 lacto-N-biosidase from Bifidobacterium bifidum. J Biol Chem. 2013 Apr 26;288(17):11795-806. doi: 10.1074/jbc.M112.420109. Epub, 2013 Mar 11. PMID:23479733 doi:10.1074/jbc.M112.420109