The Bacillus subtilis genes for ribonucleotide reductase are similar to the genes for the second class I NrdE/NrdF enzymes of Enterobacteriaceae

• Published in: Microbiology (Society for General Microbiology) 1996-11, Vol.142 (11), p.2995-3004
• Main Authors: Scotti, Claudio, Valbuzzi, Angela, Perego, Marta, Galizzi, Alessandro, Albertini, Alessandra M
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Bacillus subtilis - enzymology; Bacillus subtilis - genetics; Base Sequence; Chromosome Mapping; Cloning, Molecular; DNA Primers - genetics; Enterobacteriaceae - enzymology; Enterobacteriaceae - genetics; Escherichia coli - genetics; Gene Expression Regulation, Bacterial; Gene Expression Regulation, Enzymologic; Genes, Bacterial; Molecular Sequence Data; Mutation; Open Reading Frames; Operon; Phylogeny; Ribonucleotide Reductases - classification; Ribonucleotide Reductases - genetics; Sequence Homology, Amino Acid; Species Specificity
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/13500872-142-11-2995

1 Dipartimento di Genetica e Microbiologia, A. Buzzati Traverso Università degli Studi di Pavia, Italy 2 Dipartimento Farmaceutico, Università degli Studi di Parma, Parma, Italy ABSTRACT We have cloned and sequenced the nrd (nucleotide reductase) locus of Bacillus subtilis. The locus seems to be organized in an operon comprising four ORFs. The first three encode polypeptides highly similar to the product of the coding sequences characterizing the nrdEF operons of Enterobacteriaceae. The sequencing of the conditional lethal mutation ts-A13, localized in the nrdE cistron, and the lethality of insertional mutations targeted in the internal region of nrdE and nrdF, demonstrated the essential role of this locus. The fourth ORF, ymaB, part of the putative operon, which is not similar to any known protein, is also essential. The regulation of expression of the operon, monitored by lacZ transcriptional fusions, is similar to the regulation of the functionally relevant nrdAB operon of Escherichia coli. The operon was induced by thymidine starvation and its expression was directly or indirectly affected by RecA function. Genetic and functional analysis strongly indicates that in B. subtilis the class I ribonucleotide reductase encoded by this nrd operon is evolutionary distant from the homologous class I enzyme of Enterobacteria. 3 Author for correspondence: Alessandra M. Albertini. Tel: [phone]. Fax: [phone]. e-mail: [e-mail] Keywords: Bacillus subtilis , genome sequencing, ribonucleotide reductase, nrdEF operon, ts-A13 mutation Present address: The Scripps Research Institute, Division of Cell Biology, La Jolla, CA 92037, USA. Present address: IGBM, 19 rue C. Roux, CH 1005 Lausanne, Switzerland.