22OZ

Structural insights into HpaR-mediated recognition of hrpX and hrpG in Xanthomonas campestris pv. campestris

Summary for 22OZ

• Entry DOI: 10.2210/pdb22oz/pdb
• Descriptor: Transcriptional regulator marR family (2 entities in total)
• Functional Keywords: hpar activity, marr family, type iii secretion system, xanthomonas campestris, transcription
• Biological source: Xanthomonas campestris pv. campestris (strain ATCC 33913 / DSM 3586 / NCPPB 528 / LMG 568 / P 25)
• Total number of polymer chains: 8
• Total formula weight: 147627.17

Authors

Fu, Q.,Ming, Z. (deposition date: 2026-01-19, release date: 2026-03-11)

Primary citation

Zuo, M.,Guo, Q.,Ning, X.,Wei, J.,Huang, X.,Zhang, D.,Su, Z.,Ming, Z.,Fu, Q.
Structural insights into HpaR-mediated recognition of hrpX and hrpG in Xanthomonas campestris pv. campestris.
Biochem.Biophys.Res.Commun., 806:153429-153429, 2026

PubMed Abstract: HpaR is a transcriptional regulator belonging to the MarR family, which modulates bacterial virulence. Here, we report the biochemical and structural characterization of HpaR in Xanthomonas campestris pv. campestris (XcHpaR) and build a complex between HpaR and DNA. Our study revealed that XcHpaR can bind upstream of the divergently transcribed hrpX and hrpG genes and activate their transcription in vitro. Structural analysis of the XcHpaR dimer indicates that the monomer possesses an additional extended N-terminal α-helix (α0). Additionally, structural comparison uncovers that a winged-loop conformational change in the DNA-binding domain is essential for XcHpaR activation. Moreover, five key residues (K37, S53, K83, R89, R110) participate in DNA recognition, with R110 being highly conserved within the MarR family. This study provides valuable insights about the DNA recognition of XcHpaR and expands our understanding of the regulatory role of HpaR.

PubMed: 41666606
DOI: 10.1016/j.bbrc.2026.153429

Experimental method

X-RAY DIFFRACTION (2.511 Å)