7F2N

Crystal structure of SSB from Klebsiella pneumonia.

This is a non-PDB format compatible entry.

Summary for 7F2N

• Entry DOI: 10.2210/pdb7f2n/pdb
• Descriptor: Single-stranded DNA-binding protein (2 entities in total)
• Functional Keywords: single-stranded dna-binding protein, ssb, dna binding protein
• Biological source: Klebsiella pneumoniae subsp. pneumoniae (strain ATCC 700721 / MGH 78578)
• Total number of polymer chains: 4
• Total formula weight: 78230.08

Authors

Lin, E.S.,Huang, Y.H.,Huang, C.Y. (deposition date: 2021-06-11, release date: 2021-11-10, Last modification date: 2023-11-29)

Primary citation

Lin, E.S.,Huang, Y.H.,Huang, C.Y.
Characterization of the Chimeric PriB-SSBc Protein.
Int J Mol Sci, 22:-, 2021

PubMed Abstract: PriB is a primosomal protein required for the replication fork restart in bacteria. Although PriB shares structural similarity with SSB, they bind ssDNA differently. SSB consists of an N-terminal ssDNA-binding/oligomerization domain (SSBn) and a flexible C-terminal protein-protein interaction domain (SSBc). Apparently, the largest difference in structure between PriB and SSB is the lack of SSBc in PriB. In this study, we produced the chimeric PriB-SSBc protein in which PriB (KpPriB) was fused with SSBc of SSB (KpSSB) to characterize the possible SSBc effects on PriB function. The crystal structure of KpSSB was solved at a resolution of 2.3 Å (PDB entry 7F2N) and revealed a novel 114-GGRQ-117 motif in SSBc that pre-occupies and interacts with the ssDNA-binding sites (Asn14, Lys74, and Gln77) in SSBn. As compared with the ssDNA-binding properties of KpPriB, KpSSB, and PriB-SSBc, we observed that SSBc could significantly enhance the ssDNA-binding affinity of PriB, change the binding behavior, and further stimulate the PriA activity (an initiator protein in the pre-primosomal step of DNA replication), but not the oligomerization state, of PriB. Based on these experimental results, we discuss reasons why the properties of PriB can be retrofitted when fusing with SSBc.

PubMed: 34639195
DOI: 10.3390/ijms221910854

Experimental method

X-RAY DIFFRACTION (2.35 Å)