title: Galactomannan hydrolysis and mannose metabolism in Cellvibrio mixtus.
abstract: Galactomannan hydrolysis results from the concerted action of microbial endo-mannanases, manosidases and alpha-galactosidases and is a mechanism of intrinsic biological importance. Here we report the identification of a gene cluster in the aerobic soil bacterium Cellvibrio mixtus encoding enzymes involved in the degradation of this polymeric substrate. The family 27 alpha-galactosidase, termed CmAga27A, preferentially hydrolyse galactose containing polysaccharides. In addition, we have characterized an enzyme with epimerase activity, which might be responsible for the conversion of mannose into glucose. The role of the identified enzymes in the hydrolysis of galactomannan by aerobic bacteria is discussed.
authors.affiliation: CIISA - Faculdade de Medicina Veterinária, Pólo Universitário do Alto da Ajuda, Lisboa, Portugal.
authors.forename: Maria S J
authors.initials: MS
authors.lastname: Centeno
authors.forename: Catarina I P D
authors.initials: CI
authors.lastname: Guerreiro
authors.forename: Fernando M V
authors.initials: FM
authors.lastname: Dias
authors.forename: Carl
authors.initials: C
authors.lastname: Morland
authors.forename: Louise E
authors.initials: LE
authors.lastname: Tailford
authors.forename: Arun
authors.initials: A
authors.lastname: Goyal
authors.forename: José A M
authors.initials: JA
authors.lastname: Prates
authors.forename: Luís M A
authors.initials: LM
authors.lastname: Ferreira
authors.forename: Rui M H
authors.initials: RM
authors.lastname: Caldeira
authors.forename: Emmanuel F
authors.initials: EF
authors.lastname: Mongodin
authors.forename: Karen E
authors.initials: KE
authors.lastname: Nelson
authors.forename: Harry J
authors.initials: HJ
authors.lastname: Gilbert
authors.forename: Carlos M G A
authors.initials: CM
authors.lastname: Fontes
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D020633:Cellvibrio / Q000201:enzymology / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005690:Galactose / Q000031:analogs & derivatives; D006868:Hydrolysis; D008351:Mannans / Q000378:metabolism*; D008358:Mannose / Q000378:metabolism*; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000502:physiology; D010802:Phylogeny; D019998:Racemases and Epimerases / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D016415:Sequence Alignment; D000519:alpha-Galactosidase / Q000235:genetics / Q000378:metabolism / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D008351:Mannans; C012990:galactomannan; D000519:alpha-Galactosidase; D019998:Racemases and Epimerases; D008358:Mannose; D005690:Galactose