The adc locus, which affects competence for genetic transformation in Streptococcus pneumoniae, encodes an ABC transporter with a putative lipoprotein homologous to a family of streptococcal adhesins

Res Microbiol. 1997 Feb;148(2):119-31. doi: 10.1016/S0923-2508(97)87643-7.


To identify new components involved in the phenomenon of transformation in Streptococcus pneumoniae, a library of potential mutants has been generated by random insertion of an erythromycin resistance gene. Transformation-deficient mutants were screened using an in situ colony transformation test. The adc locus, which was identified in this search, was cloned and sequenced. Sequence analysis revealed a putative operon of three ORFs (adcC, adcB and adcA) with homology to ATP-binding cassette (ABC) transport operons encoding streptococcal adhesins such as ScaA of S. gordonii and FimA of S. parasanguis. adcA can encode a lipoprotein of 313 amino acid residues containing a putative metal-binding site. The polypeptide shows about 30% sequence identity with ScaA and FimA. We discuss evidence which leads us to propose that AdcA, together with a set of 14 proteins including ScaA, FimA and homologous adhesins, defines a new family of external solute-binding proteins, cluster 9, specific for metals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / genetics*
  • Amino Acid Sequence
  • Bacterial Adhesion*
  • Bacterial Proteins / genetics
  • Cloning, Molecular
  • Fimbriae Proteins*
  • Lipoproteins / genetics*
  • Membrane Proteins / genetics
  • Metals
  • Molecular Sequence Data
  • Mutagenesis, Insertional
  • Mutation
  • Open Reading Frames / genetics
  • Operon / genetics
  • Phylogeny
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Streptococcus pneumoniae / genetics*
  • Transformation, Bacterial / genetics*


  • ATP-Binding Cassette Transporters
  • AdcA protein, Streptococcus
  • AdcB protein, Streptococcus
  • AdcC protein, Streptococcus
  • Bacterial Proteins
  • Lipoproteins
  • Membrane Proteins
  • Metals
  • ScaA protein, Streptococcus gordonii
  • fimbrillin
  • Fimbriae Proteins

Associated data

  • GENBANK/Z71552