EVIDENCE FOR POSTTRANSLATIONAL TRANSLOCATION OF BETA-LACTAMASE ACROSS THE BACTERIAL INNER MEMBRANE
EVIDENCE FOR POSTTRANSLATIONAL TRANSLOCATION OF BETA-LACTAMASE ACROSS THE BACTERIAL INNER MEMBRANE
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DOI：
10.1016/0092-8674(82)90294-x
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发表时间：
1982-01-01
期刊：
影响因子：
64.5
通讯作者：
BOTSTEIN, D
中科院分区：
文献类型：
--
作者：
KOSHLAND, D;BOTSTEIN, D
β的分泌-研究了携带结构基因野生型和突变型等位基因的P22噬菌体感染鼠伤寒沙门氏菌中的内酰胺酶。细胞位置的前体和成熟产物的野生型和温度敏感性和链终止突变体进行了分析，通过细胞分馏和胰蛋白酶的可及性在完整的和裂解的原生质球。发现野生型和所有这些突变体的前体（它们都不改变信号肽）被隔离在细胞内，而所有成熟形式至少部分地被易位穿过内膜。大多数β-内酰胺酶分子在完成翻译后穿过膜。β-的羧基末端内酰胺酶显然不是穿过内膜移位所必需的，但是对于蛋白质作为可溶性物质出现在周质中是必需的。
Secretion of .beta.-lactamase was studied in Salmonella typhimurium infected with P22 phage carrying wild-type and mutant alleles of the structural gene. Cellular location of precursor and mature products of wild-type and temperature-sensitive and chain-terminating mutants was analyzed by cell fractionation and by trypsin accessibility in intact and lysed spheroplasts. The precursors of wild-type and all these mutants (none of which alter the signal peptide) are found sequestered within the cell, while all the mature forms have at least partially been translocated across the inner membrane. Most .beta.-lactamase molecules traverse the membrane after completion of their translation. The carboxyl terminus of .beta.-lactamase is apparently not required for translocation across the inner membrane but is required for the protein to appear in the periplasm as a soluble species.