A distinct single-stranded DNA-binding protein encoded by the Lactococcus lactis bacteriophage bIL67.
Single-stranded binding proteins (SSBs) are found to participate in various processes of DNA metabolism in all known organisms. We describe here a SSB protein encoded by the Lactococcus lactis phage bIL67 orf14 gene. It is the first noted attempt at characterizing a SSB protein from a lactococcal phage. The purified Orf14(bIL67) binds unspecifically to ssDNA with the same high affinity as the canonical Bacillus subtilis SSB. Electrophoretic mobility-shift assays performed with mutagenized Orf14(bIL67) protein derivatives suggest that ssDNA-binding occurs via a putative OB-fold structure predicted by three-dimensional modeling. The native Orf14(bIL67) forms homotetramers as determined by gel filtration studies. These results allow distinguishing the first lactococcal phage protein with single-strand binding affinity, which defines a novel cluster of phage SSBs proteins. The possible role of Orf14(bIL67) in phage multiplication cycle is also discussed.
Szczepanska
Agnieszka K
AK
INRA, Laboratoire de Génétique Microbienne, Domaine de Vilvert, 78352 Jouy en Josas Cedex, France.
Bidnenko
Elena
E
Płochocka
Danuta
D
McGovern
Stephen
S
Ehrlich
S Dusko
SD
Bardowski
Jacek
J
Polard
Patrice
P
Chopin
Marie-Christine
MC
D000595:Amino Acid Sequence; D001435:Bacteriophages / Q000235:genetics / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D013294:Lactococcus lactis / Q000821:virology*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D014764:Viral Proteins