title: Characterisation of Archaeglobus fulgidus AlkA hypoxanthine DNA glycosylase activity.
abstract: The AlkA protein from the archaebacterium Archaeglobus fulgidus was characterised with respect to release of hypoxanthine from DNA. The hypoxanthine glycosylase activity had optimal activity at 60 degrees C at pH 5.0. The enzyme released hypoxanthine from substrates with a preference for dI:dG >> dI:dT > dI:dC > dI:dA. The presence of a mismatch on either side of the dIMP in the substrate reduced excision efficiency of the hypoxanthine residue at neutral pH, while a mismatch on both sides of the dIMP resulted in total loss of excision. Release of hypoxanthine from DNA required a minimum of two bases on the 5' side and four bases on the 3' side of the dIMP residue.
authors.affiliation: Department of Biochemistry, University College, Cork, Ireland.
authors.forename: Colin
authors.initials: C
authors.lastname: Mansfield
authors.forename: Sinéad M
authors.initials: SM
authors.lastname: Kerins
authors.forename: Tommie V
authors.initials: TV
authors.lastname: McCarthy
mesh_terms: D019608:Archaeoglobales / Q000201:enzymology*; D020137:Base Pair Mismatch; D001483:Base Sequence; D019641:DNA, Archaeal; D006026:Glycoside Hydrolases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D019271:Hypoxanthine / Q000378:metabolism
chemical_list: D019641:DNA, Archaeal; D019271:Hypoxanthine; D006026:Glycoside Hydrolases; C035336:DNA-deoxyinosine glycosidase