2L8B

TraI (381-569)

Summary for 2L8B

• Entry DOI: 10.2210/pdb2l8b/pdb
• NMR Information: BMRB: 16971
• Descriptor: Protein traI (1 entity in total)
• Functional Keywords: recd, hydrolase
• Biological source: Escherichia coli
• Cellular location: Cytoplasm (Probable): P14565
• Total number of polymer chains: 1
• Total formula weight: 20494.22

Authors

Wright, N.T.,Raththagala, M.U.,Edwards, S.,Krueger, S.,Schildbach, J.F. (deposition date: 2011-01-07, release date: 2012-01-11, Last modification date: 2024-05-15)

Primary citation

Wright, N.T.,Raththagala, M.,Hemmis, C.W.,Edwards, S.,Curtis, J.E.,Krueger, S.,Schildbach, J.F.
Solution structure and small angle scattering analysis of TraI (381-569).
Proteins, 80:2250-2261, 2012

PubMed Abstract: TraI, the F plasmid-encoded nickase, is a 1756 amino acid protein essential for conjugative transfer of plasmid DNA from one bacterium to another. Although crystal structures of N- and C-terminal domains of F TraI have been determined, central domains of the protein are structurally unexplored. The central region (between residues 306 and 1520) is known to both bind single-stranded DNA (ssDNA) and unwind DNA through a highly processive helicase activity. Here, we show that the ssDNA binding site is located between residues 381 and 858, and we also present the high-resolution solution structure of the N-terminus of this region (residues 381-569). This fragment folds into a four-strand parallel β sheet surrounded by α helices, and it resembles the structure of the N-terminus of helicases such as RecD and RecQ despite little sequence similarity. The structure supports the model that F TraI resulted from duplication of a RecD-like domain and subsequent specialization of domains into the more N-terminal ssDNA binding domain and the more C-terminal domain containing helicase motifs. In addition, we provide evidence that the nickase and ssDNA binding domains of TraI are held close together by an 80-residue linker sequence that connects the two domains. These results suggest a possible physical explanation for the apparent negative cooperativity between the nickase and ssDNA binding domain.

PubMed: 22611034
DOI: 10.1002/prot.24114

Experimental method

SOLUTION NMR