Structural characterization of the H-NS protein from Xylella fastidiosa and its interaction with DNA

Author(s)

Rosselli-Murai, Luciana K. ^[1] ; Sforca, Mauricio L. ^[2] ; Sassonia, Rogerio C. ^[3] ; Azzoni, Adriano R. ^[1] ; Murai, Marcelo J. ^[4] ; de Souza, Anete P. ^{[4, 1]} ; Zeri, Ana C. ^[2]

Affiliation

^[1] Univ Estadual Campinas, Mol Biol & Genet Engn Ctr, BR-13083970 Campinas, SP - Brazil

^[2] Ctr Nacl Pesquisa Energia & Mat, Lab Nacl Biociencias, BR-13083970 Campinas, SP - Brazil

^[3] Univ Estadual Campinas, Inst Chem, BR-13083970 Campinas, SP - Brazil

^[4] Univ Estadual Campinas, Inst Biol, Dept Plant Biol, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: Archives of Biochemistry and Biophysics; v. 526, n. 1, p. 22-28, OCT 1 2012.
• Web of Science Citations: 1

Abstract

The nucleoid-associated protein H-NS is a major component of the bacterial nucleoid involved in DNA compaction and transcription regulation. The NMR solution structure of the Xylella fastidiosa H-NS C-terminal domain (residues 56-134) is presented here and consists of two beta-strands and two alpha helices, with one loop connecting the two beta-strands and a second loop connecting the second beta strand and the first helix. The amide H-1 and N-15 chemical shift signals for a sample of XfH-NS56-134 were monitored in the course of a titration series with a 14-bp DNA duplex. Most of the residues involved in contacts to DNA are located around the first and second loops and in the first helix at a positively charged side of the protein surface. The overall structure of the Xylella H-NS C-terminal domain differ significantly from Escherichia coil and Salmonella enterica H-NS proteins, even though the DNA binding motif in loop 2 adopt similar conformation, as well as beta-strand 2 and loop 1. Interestingly, we have also found that the DNA binding site is expanded to include helix 1, which is not seen in the other structures. (C) 2012 Elsevier Inc. All rights reserved. (AU)