Genetic transformation in Streptococcus pneumoniae: nucleotide sequence analysis shows comA, a gene required for competence induction, to be a member of the bacterial ATP-dependent transport protein family.
The complete nucleotide sequence of comA, a gene required for induction of competence for genetic transformation in Streptococcus pneumoniae, was determined by using plasmid DNA templates and synthetic oligonucleotide primers. The sequence contained a single large open reading frame, ORF1, of 2,151 bp. ORF1 was included within the comAB locus previously mapped genetically and accounted for 50% of its extent. The predicted molecular weight of the largest polypeptide encoded within ORF1, 80,290, coincided with that measured previously (77,000) for the product of in vitro transcription-translation of the cloned comA locus. A Shine-Dalgarno sequence (AAAGGAG, delta G = -14 kcal) lay immediately upstream of ORF1. A sequence (TTtAat-17 bp-TAaAAT) similar to the Escherichia coli sigma 70 promoter consensus was located 410 bp upstream of ORF1. The deduced protein sequence of ComA showed a very strong similarity to the E. coli hemolysin secretion protein, HlyB, and strong similarities to other members of the family of ATP-dependent transport proteins, including the mammalian multidrug resistance P-glycoprotein. These similarities suggest that ComA functions in the transport of some molecule, possibly pneumococcal competence factor itself.
Hui
F M
FM
Department of Biological Sciences, University of Illinois, Chicago 60680.
Morrison
D A
DA
D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics*; D004268:DNA-Binding Proteins; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D013296:Streptococcus pneumoniae / Q000235:genetics* / Q000378:metabolism; D014169:Transformation, Bacterial
D001426:Bacterial Proteins; D002352:Carrier Proteins; C061262:ComA protein, Bacteria; D004268:DNA-Binding Proteins; D000255:Adenosine Triphosphate