Mézes P S, Yang Y Q, Hussain M, Lampen J O
FEBS Lett. 1983 Sep 19;161(2):195-200. doi: 10.1016/0014-5793(83)81006-0.
The gene, penPC, for beta-lactamase I of Bacillus cereus 569/H has been cloned and its expression studied in Escherichia coli. The protein product from the in vitro translation of penPC was shown by gel electrophoresis to have an Mr of 36 000 which is larger than the in vivo products found in B. cereus and E. coli. The DNA sequence of the signal region was determined. It revealed that the smallest known mature form present in B. cereus culture fluids is preceded by 45-48 amino acids in pre-beta-lactamase I, considering that there are 3 initiation codons in the same reading frame, one or more of which might be initiating translation. Unlike the Bacillus licheniformis 749/C beta-lactamase, which has a membrane-bound thioether lipoprotein form, the single Cys residue in the B. cereus beta-lactamase I signal sequence is unmodified and a single processed form of the enzyme is present in E. coli cells carrying penPC.
蜡样芽孢杆菌569/H的β-内酰胺酶I基因penPC已被克隆，并在大肠杆菌中对其表达进行了研究。通过凝胶电泳显示，penPC体外翻译产生的蛋白质产物的相对分子质量为36000，大于在蜡样芽孢杆菌和大肠杆菌中发现的体内产物。测定了信号区的DNA序列。结果表明，考虑到在同一阅读框中有3个起始密码子，其中一个或多个可能起始翻译，蜡样芽孢杆菌培养液中存在的已知最小成熟形式在β-内酰胺酶I前体中有45 - 48个氨基酸。与具有膜结合硫醚脂蛋白形式的地衣芽孢杆菌749/Cβ-内酰胺酶不同，蜡样芽孢杆菌β-内酰胺酶I信号序列中的单个半胱氨酸残基未被修饰，并且在携带penPC的大肠杆菌细胞中存在该酶的单一加工形式。
