THE ROLE OF CYSTEINE RESIDUES IN THE TRANSPORT OF MERCURIC IONS BY THE TN501 MERT AND MERP MERCURY-RESISTANCE PROTEINS

被引:71
作者
MORBY, AP
HOBMAN, JL
BROWN, NL
机构
[1] Microbial Molecular Genetics and Cell Biology Group, School of Biological Sciences, University of Birmingham, Birmingham, B15 2TT, Edgbaston
关键词
D O I
10.1111/j.1365-2958.1995.mmi_17010025.x
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Each cysteine residue in the MerT and MerP polypeptides of bacterial transposon Tn501 was replaced by serine, and the mercury-resistance phenotypes of the mutants were determined in Escherichia coli. Cys-24 and Cys-25 in the first transmembrane region of MerT were essential for transport of mercuric ions through the cytoplasmic membrane, and mutations Cys-76-Ser, Cys-82-Ser or Gly-38-Asp in MerT or Cys-36-Ser in MerP all reduced transport and resistance. Deletion of the merP gene slightly reduced mercuric ion resistance and transport, whereas a Cys-33-Ser mutation in MerP appears to block transport of mercuric ions by MerT. The effects of deleting merP on mutations in merT were tested. The 116-amino-acid MerT protein is sufficient for mercuric ion transport across the cytoplasmic membrane.
引用
收藏
页码:25 / 35
页数:11
相关论文
共 53 条
  • [31] C-TERMINAL CYSTEINES OF TN501 MERCURIC ION REDUCTASE
    MOORE, MJ
    MILLER, SM
    WALSH, CT
    [J]. BIOCHEMISTRY, 1992, 31 (06) : 1677 - 1685
  • [32] MUTAGENESIS OF THE N-TERMINAL AND C-TERMINAL CYSTEINE PAIRS OF TN501 MERCURIC ION REDUCTASE - CONSEQUENCES FOR BACTERIAL DETOXIFICATION OF MERCURIALS
    MOORE, MJ
    WALSH, CT
    [J]. BIOCHEMISTRY, 1989, 28 (03) : 1183 - 1194
  • [33] MUKHOPADHYAY D, 1991, J BIOL CHEM, V266, P18538
  • [34] GENE COPY NUMBER EFFECTS IN THE MER OPERON OF PLASMID-NR1
    NAKAHARA, H
    KINSCHERF, TG
    SILVER, S
    MIKI, T
    EASTON, AM
    ROWND, RH
    [J]. JOURNAL OF BACTERIOLOGY, 1979, 138 (01) : 284 - 287
  • [35] HYPERSENSITIVITY TO HG2+ AND HYPER-BINDING ACTIVITY ASSOCIATED WITH CLONED FRAGMENTS OF THE MERCURIAL RESISTANCE OPERON OF PLASMID-NR1
    NAKAHARA, H
    SILVER, S
    MIKI, T
    ROWND, RH
    [J]. JOURNAL OF BACTERIOLOGY, 1979, 140 (01) : 161 - 166
  • [36] RESISTANCE TRANSFER AGENTS IN SHIGELLA
    NAKAYA, R
    NAKAMURA, A
    MURATA, Y
    [J]. BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 1960, 3 (06) : 654 - 659
  • [37] NIBHRIAN N, 1986, GENE, V42, P323
  • [38] CONSTRUCTION AND CHARACTERIZATION OF A MERCURY-INDEPENDENT MERR ACTIVATOR (MERR(AC)) - TRANSCRIPTIONAL ACTIVATION IN THE ABSENCE OF HG(II) IS ACCOMPANIED BY DNA DISTORTION
    PARKHILL, J
    ANSARI, AZ
    WRIGHT, JG
    BROWN, NL
    OHALLORAN, TV
    [J]. EMBO JOURNAL, 1993, 12 (02) : 413 - 421
  • [39] RABENSTEIN DL, 1989, METAL COMPLEXES GLUT
  • [40] PURIFICATION AND PROPERTIES OF THE MERCURIC-ION-BINDING PROTEIN MERP
    SAHLMAN, L
    JONSSON, BH
    [J]. EUROPEAN JOURNAL OF BIOCHEMISTRY, 1992, 205 (01): : 375 - 381