Open AccessMolecular characterization of PcpA: a novel choline‐binding protein of Streptococcus pneumoniae
Author(s) -
SánchezBeato Ana R.,
López Rubens,
Garcıća José L.
Publication year - 1998
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1998.tb13087.x
Subject(s) - biology , amino acid , gene , start codon , biochemistry , binding protein , peptide sequence , escherichia coli , streptococcus pneumoniae , microbiology and biotechnology , genetics , bacteria , messenger rna
The gene pcpA that encodes a novel pneumococcal choline‐binding protein has been cloned and characterized. Northern blot analysis revealed that pcpA is expressed during the exponential phase of growth of pneumococci as a monocistronic transcript of about 2.3 kb. The transcription start site has been located 132 bp upstream of the start codon and the proposed −35 and −10 boxes that are highly similar to those of the typical σ 70 promoters from Escherichia coli . This gene encodes a putative 79 kDa protein that contains a typical C‐terminal choline‐binding domain (ChBD). The ChBD of PcpA is built up by 11 identical motifs of 20 amino acids plus a tail of 19 amino acids, which represents the longest ChBD that has been characterized so far. Interestingly, two tandem arrays of five characteristic amphipatic leucine reach repeats (LRRs) of 22–26 amino acids in length have been found in the N‐terminal region of PcpA. Since LRRs have been proposed to be involved in protein‐protein and protein‐lipid interactions our finding suggests a role for PcpA in pneumococcal adhesion.