5X0O

Regulatory domain of AphB treated with Cumene hydroperoxide from Vibrio vulnificus

Summary for 5X0O

• Entry DOI: 10.2210/pdb5x0o/pdb
• Related: 5X0N
• Descriptor: LysR family transcriptional regulator (1 entity in total)
• Functional Keywords: aphb, lysr-type, transcriptional regulator, tcpph activation, transcription
• Biological source: Vibrio vulnificus
• Total number of polymer chains: 6
• Total formula weight: 140417.88

Authors

Song, S.,Park, N.,Ha, N.-C. (deposition date: 2017-01-22, release date: 2017-05-10, Last modification date: 2023-11-22)

Primary citation

Park, N.,Song, S.,Choi, G.,Jang, K.K.,Jo, I.,Choi, S.H.,Ha, N.-C.
Crystal Structure of the Regulatory Domain of AphB from Vibrio vulnificus, a Virulence Gene Regulator
Mol. Cells, 40:299-306, 2017

PubMed Abstract: The transcriptional activator AphB has been implicated in acid resistance and pathogenesis in the food borne pathogens and . To date, the full-length AphB crystal structure of has been determined and characterized by a tetrameric assembly of AphB consisting of a DNA binding domain and a regulatory domain (RD). Although acidic pH and low oxygen tension might be involved in the activation of AphB, it remains unknown which ligand or stimulus activates AphB at the molecular level. In this study, we determine the crystal structure of the AphB RD from under aerobic conditions without modification at the conserved cysteine residue of the RD, even in the presence of the oxidizing agent cumene hydroperoxide. A cysteine to serine amino acid residue mutant RD protein further confirmed that the cysteine residue is not involved in sensing oxidative stress in vitro. Interestingly, an unidentified small molecule was observed in the inter-subdomain cavity in the RD when the crystal was incubated with cumene hydroperoxide molecules, suggesting a new ligand-binding site. In addition, we confirmed the role of AphB in acid tolerance by observing an -dependent increase in transcript level when was exposed to acidic pH. Our study contributes to the understanding of the AphB molecular mechanism in the process of recognizing the host environment.

PubMed: 28427249
DOI: 10.14348/molcells.2017.0015

Experimental method

X-RAY DIFFRACTION (2.402 Å)