Dehottay P, Dusart J, De Meester F, Joris B, Van Beeumen J, Erpicum T, Frère J M, Ghuysen J M
Eur J Biochem. 1987 Jul 15;166(2):345-50. doi: 10.1111/j.1432-1033.1987.tb13521.x.
A 1400-base DNA fragment, which contains the gene encoding the extracellular active-site serine beta-lactamase of Streptomyces albus G previously cloned into Streptomyces lividans [Dehottay et al. (1986) Gene 42, 31-36], was sequenced. The gene codes for a 314-amino-acid precursor, the N-terminal region of which has the characteristics of a signal peptide. The beta-lactamase as excreted by the host strain S. lividans PD6 has a ragged N-terminus, indicating either the presence of a leader peptidase of poor specificity or the action of an aminopeptidase. The primary structure (as deduced from the nucleotide sequence) was confirmed by amino acid sequencing of a 16-residue stretch at the amino terminus of the protein, a 12-residue stretch containing the active-site serine [De Meester et al. (1987) Biochem. J. 244, 427-432] and a 23-residue stretch obtained by trypsin digestion of the protein. The beta-lactamase belongs to class A, has three half-cystine residues (one of which occurs on the amino side of the active-site serine) and is inactivated by thiol reagents. Putative ribosome binding site and terminator region were identified.
对一个1400个碱基的DNA片段进行了测序，该片段包含以前克隆到变铅青链霉菌中的白链霉菌G细胞外活性位点丝氨酸β-内酰胺酶的编码基因[德霍泰等人（1986年），《基因》42卷，31 - 36页]。该基因编码一个314个氨基酸的前体，其N端区域具有信号肽的特征。宿主菌株变铅青链霉菌PD6分泌的β-内酰胺酶N端参差不齐，这表明存在特异性较差的前导肽酶或氨肽酶的作用。通过对蛋白质N端16个残基片段、包含活性位点丝氨酸的12个残基片段[德梅斯特等人（1987年），《生物化学杂志》244卷，427 - 432页]以及通过蛋白质胰蛋白酶消化获得的23个残基片段进行氨基酸测序，证实了（从核苷酸序列推导的）一级结构。该β-内酰胺酶属于A类，有三个半胱氨酸残基（其中一个位于活性位点丝氨酸的氨基侧），并被硫醇试剂灭活。确定了假定核糖体结合位点和终止区。
