产氧化亚铁硫杆菌merC的大肠杆菌细胞对汞离子的摄取

Mercuric ion uptake by Escherichia coli cells producing Thiobacillus ferrooxidans merC.

作者信息

Inoue C, Kusano T, Silver S

机构信息

Laboratory of Plant Genetic Engineering, Akita Prefectural College of Agriculture, Japan.

出版信息

Biosci Biotechnol Biochem. 1996 Aug;60(8):1289-92. doi: 10.1271/bbb.60.1289.

DOI:10.1271/bbb.60.1289

PMID:8987545

Abstract

The merC gene of Thiobacillus ferrooxidans was overexpressed in Escherichia coli under the control of the tac promoter. MerC protein synthesized in E. coli has a N-terminal amino acid sequence of S-A-I-X-R-I-I-D-K-I-G-I-V-G-, which agrees with the amino acid sequence deduced from its nucleotide sequence except that an initiating methionine residue was removed. The MerC protein was localized in the particulate (membrane) cell fraction, and not in the soluble cytoplasmic fraction. E. coli cells carrying a plasmid containing the tac promoter-directed merC showed 203Hg2+ uptake in an isopropyl-1-thio-beta-D-galactopyranoside (IPTG)-dependent manner.

摘要

在 tac 启动子的控制下，氧化亚铁硫杆菌的 merC 基因在大肠杆菌中过表达。在大肠杆菌中合成的 MerC 蛋白具有 N 端氨基酸序列 S-A-I-X-R-I-I-D-K-I-G-I-V-G-，这与其核苷酸序列推导的氨基酸序列一致，只是起始甲硫氨酸残基被去除。MerC 蛋白定位于颗粒状（膜）细胞组分，而非可溶性细胞质组分。携带含有 tac 启动子指导的 merC 质粒的大肠杆菌细胞以异丙基-1-硫代-β-D-半乳糖苷（IPTG）依赖性方式表现出 203Hg2+ 摄取。