6NP6

Crystal structure of the sensor domain of the transcriptional regulator HcpR from Porphyromonas Gingivalis

Replaces:  5V3E

Summary for 6NP6

• Entry DOI: 10.2210/pdb6np6/pdb
• Descriptor: Crp/Fnr family transcriptional regulator, GLYCEROL (3 entities in total)
• Functional Keywords: beta barrel, dimerization helix, transcriptional regulator, heme binding protein, transcription
• Biological source: Porphyromonas gingivalis
• Total number of polymer chains: 2
• Total formula weight: 34486.39

Authors

Musayev, F.N.,Belvin, B.R.,Escalante, C.R.,Turner, J.,Scarsdale, J.N.,Lewis, J.P. (deposition date: 2019-01-17, release date: 2019-06-26, Last modification date: 2024-04-03)

Primary citation

Belvin, B.R.,Musayev, F.N.,Turner, J.,Scarsdale, J.N.,Escalante, C.R.,Lewis, J.P.
Nitrosative Stress Sensing in Porphyromonas gingivalis: Structure and Mechanisms of the Heme Binding Transcriptional Regulator HcpR.
Acta Crystallogr D Struct Biol, 75:437-450, 2019

PubMed Abstract: Although the HcpR regulator plays a vital step in initiation of the nitrosative stress response in many Gram-negative anaerobic bacteria, the molecular mechanisms that it uses to mediate gas sensing are not well understood. Here, a 2.6 Å resolution crystal structure of the N-terminal sensing domain of the anaerobic periodontopathogen Porphyromonas gingivalis HcpR is presented. The protein has classical features of the regulators belonging to the FNR-CRP family and contains a hydrophobic pocket in its N-terminal sensing domain. It is shown that heme bound to HcpR exhibits heme iron as a hexacoordinate system in the absence of nitric oxide (NO) and that upon nitrosylation it transitions to a pentacoordinate system. Finally, small-angle X-ray scattering experiments on full-length HcpR reveal that the C-terminal DNA-binding domain of HcpR has a high degree of interdomain flexibility.

PubMed: 30988260
DOI: 10.1107/S205979831900264X

Experimental method

X-RAY DIFFRACTION (2.6 Å)