PDBsum entry 2wkc

DNA binding protein

PDB id: 2wkc

Contents

Protein chains

90 a.a. *

89 a.a. *

Waters ×28

* Residue conservation analysis

PDB id:

2wkc

Name:

DNA binding protein

Title:

Crystal structure from a single-stranded DNA binding protein from the lactococcal phage p2

Structure:

Orf34p2. Chain: a, b, c, d. Fragment: residues 15-131. Engineered: yes

Source:

Lactococcus phage p2. Organism_taxid: 254252. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.60Å R-factor: 0.197 R-free: 0.251

Authors:

E.Scaltriti,C.Cambillau,M.Ortiz-Lombardia

Key ref:

E.Scaltriti et al. (2009). Structure and function of phage p2 ORF34(p2), a new type of single-stranded DNA binding protein. Mol Microbiol, 73, 1156-1170. PubMed id: 19719513

Date:

09-Jun-09 Release date: 15-Sep-09

Protein chains

Q09WL7  (Q09WL7_9CAUD) -  SSB protein from Lactococcus virus jj50

Seq: 131 a.a.

Struc: 90 a.a.*

Protein chain

Q09WL7  (Q09WL7_9CAUD) -  SSB protein from Lactococcus virus jj50

Seq: 131 a.a.

Struc: 89 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

Mol Microbiol 73:1156-1170 (2009)

PubMed id: 19719513

Structure and function of phage p2 ORF34(p2), a new type of single-stranded DNA binding protein.

E.Scaltriti, M.Tegoni, C.Rivetti, H.Launay, J.Y.Masson, A.H.Magadan, D.Tremblay, S.Moineau, R.Ramoni, J.Lichière, V.Campanacci, C.Cambillau, M.Ortiz-Lombardía.

ABSTRACT

Lactococcus lactis, a Gram-positive bacterium widely used by the dairy industry, is subject to infection by a diverse population of virulent phages, predominantly by those of the 936 group, including the siphovirus phage p2. Confronted with the negative impact of phage infection on milk fermentation, the study of the biology of lactococcal provides insight from applied and fundamental perspectives. We decided to characterize the product of the orf34 gene from lactococcus phage p2, which was considered as a candidate single-stranded DNA binding protein (SSB) due to its localization downstream of a gene coding for a single-strand annealing protein. Two-dimensional gel electrophoresis showed that ORF34(p2) is expressed in large amounts during the early phases of phage infection, suggesting an important role in this process. Gel-shift assays, surface plasmon resonance and atomic force microscopy demonstrated that ORF34(p2) interacts with single-strand DNA with nanomolar affinity. We also determined the crystal structure of ORF34(p2) and showed that it bears a variation of the typical oligonucleotide/oligosaccharide binding-fold of SSBs. Finally, we found that ORF34(p2) is able to stimulate Escherichia coli RecA-mediated homologous recombination. The specific structural and biochemical properties that distinguish ORF34(p2) from other SSB proteins are discussed.