title: Characterization of a recombinant (-)γ-lactamase from Microbacterium hydrocarbonoxydans.
abstract: A (-)γ-lactamase, Mhg, from Microbacterium hydrocarbonoxydans was over-expressed in E. coli and was characterized after purification. The maximum activity was at pH 8.0 and 60°C and the half life of Mhg was ~30 min at 75°C. The enzyme was activated by DTT. The catalytic triad of the (-)γ-lactamase is comprised of residues Ser98, Asp230, and His259 and an oxyanion hole was formed by Tyr32 and Met99 according to the alignment results. Under native conditions, the (-)γ-lactamase consists of two 31 kDa homodimers.
authors.affiliation: State Key Laboratory of Chemical Resources Engineering, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Yang
authors.forename: Qian
authors.initials: Q
authors.lastname: Gao
authors.forename: Sheng
authors.initials: S
authors.lastname: Wu
authors.forename: Jianjun
authors.initials: J
authors.lastname: Wang
authors.forename: Guojun
authors.initials: G
authors.lastname: Zheng
mesh_terms: D000192:Actinomycetales / Q000201:enzymology* / Q000235:genetics*; D000581:Amidohydrolases / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D020134:Catalytic Domain; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004229:Dithiothreitol / Q000378:metabolism; D020536:Enzyme Activators / Q000378:metabolism; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011487:Protein Conformation; D055503:Protein Multimerization; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D020536:Enzyme Activators; D011994:Recombinant Proteins; D000581:Amidohydrolases; C401943:gamma-lactamase; D004229:Dithiothreitol