Identification of a zinc-specific metalloregulatory protein, Zur, controlling zinc transport operons in Bacillus subtilis

被引:212
作者
Gaballa, A [1 ]
Helmann, JD [1 ]
机构
[1] Cornell Univ, Microbiol Sect, Ithaca, NY 14853 USA
关键词
D O I
10.1128/JB.180.22.5815-5821.1998
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
Zinc is an essential nutrient for all cells, but remarkably little is known regarding bacterial zinc transport and its regulation. We have identified three of the key components acting to maintain zinc homeostasis in Bacillus subtilis. Zur is a metalloregulatory protein related to the; ferric uptake repressor (Fur) family of regulators and is required for the zinc-specific repression of two operons implicated in zinc uptake, yciC and ycdHIyceA. A zur mutant overexpresses the 45-kDa YciC membrane protein, and purified Zur binds specifically, and in a zinc-responsive manner, to an operator site overlapping the yciC control region. A similar operator precedes the ycdH-containing operon, which encodes an ABC transporter. Two lines of evidence suggest that the ycdH operon encodes a high-affinity zinc transporter whereas YeiC may function as part of a lower-affinity pathway. First, a ycdH mutant is impaired in growth in low-zinc medium, and this growth defect is exacerbated by the additional presence of a yciC mutation. Second, mutation of ycdH, but not yciC, alters the regulation of both the yciC and ycdH operons such that much higher levels of exogenous zinc are required for repression. We conclude that Zur is a Fur-like repressor that controls the expression of two zinc homeostasis operons in response to zinc. Thus, Fur-like regulators control zinc homeostasis in addition to their previously characterized roles in regulating iron homeostasis, acid tolerance responses, and oxidative stress functions.
引用
收藏
页码:5815 / 5821
页数:7
相关论文
共 44 条
[1]   Gapped BLAST and PSI-BLAST: a new generation of protein database search programs [J].
Altschul, SF ;
Madden, TL ;
Schaffer, AA ;
Zhang, JH ;
Zhang, Z ;
Miller, W ;
Lipman, DJ .
NUCLEIC ACIDS RESEARCH, 1997, 25 (17) :3389-3402
[2]   MOLECULAR MECHANISM OF REGULATION OF SIDEROPHORE-MEDIATED IRON ASSIMILATION [J].
BAGG, A ;
NEILANDS, JB .
MICROBIOLOGICAL REVIEWS, 1987, 51 (04) :509-518
[3]   Zinc(II) tolerance in Escherichia coli K-12: evidence that the zntA gene (o732) encodes a cation transport ATPase [J].
Beard, SJ ;
Hashim, R ;
MembrilloHernandez, J ;
Hughes, MN ;
Poole, RK .
MOLECULAR MICROBIOLOGY, 1997, 25 (05) :883-891
[4]   Bacillus subtilis contains multiple Fur homologues:: identification of the iron uptake (Fur) and peroxide regulon (PerR) repressors [J].
Bsat, N ;
Herbig, A ;
Casillas-Martinez, L ;
Setlow, P ;
Helmann, JD .
MOLECULAR MICROBIOLOGY, 1998, 29 (01) :189-198
[5]  
BSAT N, 1998, THESIS CORNELL U ITH
[6]   COORDINATE REGULATION OF BACILLUS-SUBTILIS PEROXIDE STRESS GENES BY HYDROGEN-PEROXIDE AND METAL-IONS [J].
CHEN, L ;
KERAMATI, L ;
HELMANN, JD .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1995, 92 (18) :8190-8194
[7]   METALLOREGULATION IN BACILLUS-SUBTILIS - ISOLATION AND CHARACTERIZATION OF 2 GENES DIFFERENTIALLY REPRESSED BY METAL-IONS [J].
CHEN, L ;
JAMES, LP ;
HELMANN, JD .
JOURNAL OF BACTERIOLOGY, 1993, 175 (17) :5428-5437
[8]   Crystal structure of the cyanobacterial metallothionein repressor SmtB: A model for metalloregulatory proteins [J].
Cook, WJ ;
Kar, SR ;
Taylor, KB ;
Hall, LM .
JOURNAL OF MOLECULAR BIOLOGY, 1998, 275 (02) :337-346
[9]   STRUCTURAL DYNAMICS AND FUNCTIONAL DOMAINS OF THE FUR PROTEIN [J].
COY, M ;
NEILANDS, JB .
BIOCHEMISTRY, 1991, 30 (33) :8201-8210
[10]   NUCLEOTIDE-SEQUENCE AND GENETIC-ANALYSIS OF A 13.1-KILOBASE-PAIR PSEUDOMONAS-DENITRIFICANS DNA FRAGMENT CONTAINING 5 COB GENES AND IDENTIFICATION OF STRUCTURAL GENES ENCODING COB(I)ALAMIN ADENOSYLTRANSFERASE, COBYRIC ACID SYNTHASE, AND BIFUNCTIONAL COBINAMIDE KINASE-COBINAMIDE PHOSPHATE GUANYLYLTRANSFERASE [J].
CROUZET, J ;
LEVYSCHIL, S ;
CAMERON, B ;
CAUCHOIS, L ;
RIGAULT, S ;
ROUYEZ, MC ;
BLANCHE, F ;
DEBUSSCHE, L ;
THIBAUT, D .
JOURNAL OF BACTERIOLOGY, 1991, 173 (19) :6074-6087