Structural highlights
Function
LNPA_BIFL2 Reversibly phosphorolyzes lacto-N-biose to Gal1-P and N-acetylglucosamine (GlcNAc) and galacto-N-biose to Gal1-P and N-acetylgalactosamine (GalNAc). Involved in the lacto-N-biose I/galacto-N-biose (LNB/GNB) degradation pathway, which is important for host intestinal colonization by bifidobacteria.[1] [2] [3]
Publication Abstract from PubMed
Galacto-N-biose/lacto-N-biose I phosphorylase (GLNBP) is the key enzyme in the enzymatic production of lacto-N-biose I. For the purpose of industrial use, we improved the thermostability of GLNBP by evolutionary engineering in which five substitutions in the amino acid sequence were selected from a random mutagenesis GLNBP library constructed using error-prone polymerase chain reaction. Among them, C236Y and D576V mutants showed considerably improved thermostability. Structural analysis of C236Y revealed that the hydroxyl group of Tyr236 forms a hydrogen bond with the carboxyl group of E319. The C236Y and D576V mutations together contributed to the thermostability. The C236Y/D576V mutant exhibited 20 degrees C higher thermostability than the wild type.
Directed evolution to enhance thermostability of galacto-N-biose/lacto-N-biose I phosphorylase.,Koyama Y, Hidaka M, Nishimoto M, Kitaoka M Protein Eng Des Sel. 2013 Sep 24. PMID:24065834[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kitaoka M, Tian J, Nishimoto M. Novel putative galactose operon involving lacto-N-biose phosphorylase in Bifidobacterium longum. Appl Environ Microbiol. 2005 Jun;71(6):3158-62. PMID:15933016 doi:71/6/3158
- ↑ Nishimoto M, Kitaoka M. Identification of N-acetylhexosamine 1-kinase in the complete lacto-N-biose I/galacto-N-biose metabolic pathway in Bifidobacterium longum. Appl Environ Microbiol. 2007 Oct;73(20):6444-9. Epub 2007 Aug 24. PMID:17720833 doi:http://dx.doi.org/10.1128/AEM.01425-07
- ↑ Hidaka M, Nishimoto M, Kitaoka M, Wakagi T, Shoun H, Fushinobu S. The crystal structure of galacto-N-biose/lacto-N-biose I phosphorylase: a large deformation of a TIM barrel scaffold. J Biol Chem. 2009 Mar 13;284(11):7273-83. Epub 2009 Jan 5. PMID:19124470 doi:10.1074/jbc.M808525200
- ↑ Koyama Y, Hidaka M, Nishimoto M, Kitaoka M. Directed evolution to enhance thermostability of galacto-N-biose/lacto-N-biose I phosphorylase. Protein Eng Des Sel. 2013 Sep 24. PMID:24065834 doi:http://dx.doi.org/10.1093/protein/gzt049
