The N-terminal arm of the Helicobacter pylori Ni2+-dependent transcription factor NikR is required for specific DNA binding

被引:41
作者
Benanti, Erin L. [1 ]
Chivers, Peter T. [1 ]
机构
[1] Washington Univ, Sch Med, Dept Biochem & Mol Biophys, St Louis, MO 63110 USA
关键词
D O I
10.1074/jbc.M702982200
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
The Ni2+-dependent transcription factor NikR is widespread among microbes. The two experimentally characterized NikR orthologs, from Helicobacter pylori and Escherichia coli, display vastly different regulatory capabilities in response to increased intracellular Ni2+. Here, we demonstrate that the nine-residue N-terminal arm present in H. pylori NikR plays a critical role in the expanded regulatory capabilities of this NikR family member. Specifically, the N-terminal arm is required to inhibit NikR binding to low affinity and nonspecific DNA sequences and is also linked to a cation requirement for NikR binding to the nixA promoter. Site-directed mutagenesis and arm-truncation variants of NikR indicate that two residues, Asp-7 and Asp-8, are linked to the cation requirement for binding. Pro-4 and Lys-6 are required for maximal DNA binding affinity of the full-length protein to both the nixA and ureA promoters. The N-terminal arm is highly variable among NikR family members, and these results suggest that it is an adaptable structural feature that can tune the regulatory capabilities of NikR to the nickel physiology of the microbe in which it is found.
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收藏
页码:20365 / 20375
页数:11
相关论文
共 68 条
[1]   The metal- and DNA-binding activities of Helicobacter pylori NikR [J].
Abraham, Lihor O. ;
Li, Yanjie ;
Zamble, Deborah B. .
JOURNAL OF INORGANIC BIOCHEMISTRY, 2006, 100 (5-6) :1005-1014
[2]   A SEQUENCE MOTIF IN MANY POLYMERASES [J].
ARGOS, P .
NUCLEIC ACIDS RESEARCH, 1988, 16 (21) :9909-9916
[3]   NICKEL-CONTAINING HYDROGENASE ISOENZYMES FROM ANAEROBICALLY GROWN ESCHERICHIA-COLI K-12 [J].
BALLANTINE, SP ;
BOXER, DH .
JOURNAL OF BACTERIOLOGY, 1985, 163 (02) :454-459
[4]   Synthesis and activity of Helicobacter pylori urease and catalase at low pH [J].
Bauerfeind, P ;
Garner, R ;
Dunn, BE ;
Mobley, HLT .
GUT, 1997, 40 (01) :25-30
[5]   Differential regulation of urease activity in Helicobacter hepaticus and Helicobacter pylori [J].
Belzer, C ;
Stoof, J ;
Beckwith, CS ;
Kuipers, EJ ;
Kusters, JG ;
van Vliet, AHM .
MICROBIOLOGY-SGM, 2005, 151 :3989-3995
[6]   Interactions of Arg2 in the Mnt N-terminal arm with the central and flanking regions of the mnt operator [J].
Berggrun, A ;
Sauer, RT .
JOURNAL OF MOLECULAR BIOLOGY, 2000, 301 (04) :959-973
[7]   Contributions of distinct quaternary contacts to cooperative operator binding by Mnt repressor [J].
Berggrun, A ;
Sauer, RT .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2001, 98 (05) :2301-2305
[8]   HELICOBACTER-PYLORI AND THE PATHOGENESIS OF GASTRODUODENAL INFLAMMATION [J].
BLASER, MJ .
JOURNAL OF INFECTIOUS DISEASES, 1990, 161 (04) :626-633
[9]   Metal-selective DNA-binding response of Escherichia coli NikR [J].
Bloom, SL ;
Zamble, DB .
BIOCHEMISTRY, 2004, 43 (31) :10029-10038
[10]   The MerR family of transcriptional regulators [J].
Brown, NL ;
Stoyanov, JV ;
Kidd, SP ;
Hobman, JL .
FEMS MICROBIOLOGY REVIEWS, 2003, 27 (2-3) :145-163