title: Purification, characterization and functional analysis of an endo-arabinanase (AbnA) from Bacillus subtilis.
abstract: Bacillus subtilis synthesizes at least one arabinanase encoded by the abnA gene that is able to degrade the polysaccharide arabinan. Here, we report the expression in Escherichia coli of the full-length abnA coding region with a His6-tag fused to the C-terminus. The recombinant protein was secreted to the periplasmic space and correctly processed by the E. coli signal peptidase. The substrate specificity of purified AbnA, the physico-chemical properties and kinetic parameters were determined. Functional analysis studies revealed Glu 215 as a key residue for AbnA hydrolytic activity and indicated that in addition to AbnA B. subtilis secretes other enzyme(s) able to degrade linear 1,5-alpha-l-arabinan.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida de República, Apartado 127, 2781-901 Oeiras, Portugal.
authors.forename: Teresa Fontes
authors.initials: TF
authors.lastname: Leal
authors.forename: Isabel
authors.initials: I
authors.lastname: de Sá-Nogueira
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology*; D004926:Escherichia coli / Q000235:genetics; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000302:isolation & purification* / Q000502:physiology; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000302:isolation & purification
chemical_list: D011994:Recombinant Proteins; D006026:Glycoside Hydrolases; C082526:arabinan endo-1,5-alpha-L-arabinosidase