Corynebacterium ammoniagenes class Ib ribonucleotide reductase:: transcriptional regulation of an atypical genomic organization in the nrd cluster

被引:27
作者
Torrents, E
Roca, I
Gibert, I
机构
[1] Univ Autonoma Barcelona, Inst Biotecnol & Biomed, E-08193 Barcelona, Spain
[2] Univ Autonoma Barcelona, Dept Genet & Microbiol, Grp Genet Mol Bacteriana, E-08193 Barcelona, Spain
来源
MICROBIOLOGY-SGM | 2003年 / 149卷
关键词
D O I
10.1099/mic.0.26133-0
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
Ribonucleotide reductases (RNRs) are a family of complex enzymes that play an essential role in all organisms because they catalyse de novo synthesis of deoxyribonucleotides required for DNA replication and repair. Three different classes of RNR have been described according to their metal cofactors and organic radicals. Class Ib RNR is encoded in four different genes (nrdH, nrdl, nrdE and nrdF) organized in an operon. The authors previously cloned and sequenced the genes encoding the active class Ib RNR of Corynebacterium ammoniagenes and showed that these genes are clustered in an atypical nrdEF region, which differs from that of other known class Ib enzymes because of an intergenic sequence (1171 bp) present between nrdE and nrdF. This study investigated the transcriptional organization and regulation of this nrd region by RT-PCR. Three different and independent mRNA were found (nrdHIE, nrdF and an ORF present in the intergenic region), each one being transcribed from its own promoter and being essential for normal growth. The ratio of nrdF to nrdHIE mRNA was 9.1, as determined by competitive RT-PCR; the expression of both nrdHIE and nrdF was found to be dependent on the culture growth phase, and was induced in the presence of hydroxyurea, manganese and hydrogen peroxide. This is believed to be the first direct evidence for a manganese-dependent transcriptional regulation of nrd genes. These results suggest a common and coordinated regulation of the different nrd genes, despite their being transcribed from independent promoters.
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页码:1011 / 1020
页数:10
相关论文
共 29 条
[11]   The ribonucleotide reductase system of Lactococcus lactis - Characterization of an nrdEF enzyme and a new electron transport protein [J].
Jordan, A ;
Pontis, E ;
Aslund, F ;
Hellman, U ;
Gibert, I ;
Reichard, P .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1996, 271 (15) :8779-8785
[12]   Promoter identification and expression analysis of Salmonella typhimurium and Escherichia coli nrdEF operons encoding one of two class I ribonucleotide reductases present in both bacteria [J].
Jordan, A ;
Aragall, E ;
Gibert, I ;
Barbe, J .
MOLECULAR MICROBIOLOGY, 1996, 19 (04) :777-790
[13]   Ribonucleotide reductases [J].
Jordan, A ;
Reichard, P .
ANNUAL REVIEW OF BIOCHEMISTRY, 1998, 67 :71-98
[14]   Identification and characterization of three new promoter/operators from Corynebacterium diphtheriae that are regulated by the diphtheria toxin repressor (DtxR) and iron [J].
Lee, JH ;
Wang, T ;
Ault, K ;
Liu, J ;
Schmitt, MP ;
Holmes, RK .
INFECTION AND IMMUNITY, 1997, 65 (10) :4273-4280
[15]   Analysis of transcription of the Staphylococcus aureus aerobic class Ib and anaerobic class III ribonucleotide reductase genes in response to oxygen [J].
Masalha, M ;
Borovok, I ;
Schreiber, R ;
Aharonowitz, Y ;
Cohen, G .
JOURNAL OF BACTERIOLOGY, 2001, 183 (24) :7260-7272
[16]  
Miller J.H., 1972, ASSAY BETA GALACTOSI
[17]   Expression analysis of the nrdHIEF operon from Escherichia coli -: Conditions that trigger the transcript level in vivo [J].
Monje-Casas, F ;
Jurado, J ;
Prieto-Alamo, MJ ;
Holmgren, A ;
Pueyo, C .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2001, 276 (21) :18031-18037
[18]   UNBALANCED GROWTH DEATH DUE TO DEPLETION OF MN2+ IN BREVIBACTERIUM AMMONIAGENES [J].
OKA, T ;
UDAGAWA, K ;
KINOSHIT.K .
JOURNAL OF BACTERIOLOGY, 1968, 96 (05) :1760-&
[19]   Characterization of a manganese-dependent regulatory protein, TroR, from Treponema pallidum [J].
Posey, JE ;
Hardham, JM ;
Norris, SJ ;
Gherardini, FC .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1999, 96 (19) :10887-10892
[20]   Subdivision of the helix-turn-helix GntR family of bacterial regulators in the FadR, HutC, MocR, and YtrA subfamilies [J].
Rigali, S ;
Derouaux, A ;
Giannotta, F ;
Dusart, J .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2002, 277 (15) :12507-12515