title: Mycobacterium smegmatis dnaA region and autonomous replication activity.
abstract: Two key elements that are thought to be required for replication initiation in eubacteria are the DnaA protein, a trans-acting factor, and the replication origin, a cis-acting element. As a first step in studying the replication initiation process in mycobacteria, we have isolated a 4-kb chromosomal DNA fragment from Mycobacterium smegmatis that contains the dnaA gene. Nucleotide sequence analysis of this region revealed homologies with the rpmH gene, which codes for the ribosomal protein L34, the dnaA gene, which codes for the replication initiator protein DnaA, and the 5' end of the dnaN gene, which codes for the beta subunit of DNA polymerase III. Further, we provide evidence that when cloned into pUC18, a plasmid that is nonreplicative in M. smegmatis, the DNA fragment containing the dnaA gene and its flanking regions rendered the former capable of autonomous replication in M. smegmatis. We suggest that the M. smegmatis chromosomal origin of replication is located within the 4-kb DNA fragment.
authors.affiliation: Department of Microbiology, University of Texas Health Center at Tyler 75710, USA.
authors.forename: M
authors.initials: M
authors.lastname: Rajagopalan
authors.forename: M H
authors.initials: MH
authors.lastname: Qin
authors.forename: D R
authors.initials: DR
authors.lastname: Nash
authors.forename: M V
authors.initials: MV
authors.lastname: Madiraju
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D003001:Cloning, Molecular; D004261:DNA Replication / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004259:DNA-Directed DNA Polymerase; D005798:Genes, Bacterial / Q000235:genetics; D008969:Molecular Sequence Data; D009161:Mycobacterium / Q000235:genetics*; D010957:Plasmids / Q000235:genetics; D018741:Replication Origin / Q000235:genetics*; D012269:Ribosomal Proteins / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C066312:DnaA protein, Bacteria; D012269:Ribosomal Proteins; C041672:ribosomal protein L34; D004259:DNA-Directed DNA Polymerase; C083980:dnaN protein, Bacteria