2BGC

PrfA-G145S, a constitutive active mutant of the Transcriptional Regulator In L.monocytogenes

Summary for 2BGC

• Entry DOI: 10.2210/pdb2bgc/pdb
• Related: 1OMI 2BEO
• Descriptor: PRFA, (2R,3S)-1,4-DIMERCAPTOBUTANE-2,3-DIOL, 2,3-DIHYDROXY-1,4-DITHIOBUTANE, ... (4 entities in total)
• Functional Keywords: bacterial infection, human pathogen, transcriptional regulator, transcription
• Biological source: LISTERIA MONOCYTOGENES
• Total number of polymer chains: 8
• Total formula weight: 219752.50

Authors

Eiting, M.,Hagelueken, G.,Schubert, W.-D.,Heinz, D.W. (deposition date: 2004-12-20, release date: 2005-04-14, Last modification date: 2023-12-13)

Primary citation

Eiting, M.,Hagelueken, G.,Schubert, W.-D.,Heinz, D.W.
The Mutation G145S in Prfa, a Key Virulence Regulator of Listeria Monocytogenes, Increases DNA-Binding Affinity by Stabilizing the Hth Motif
Mol.Microbiol., 56:433-, 2005

PubMed Abstract: Listeria monocytogenes, a Gram-positive, facultative intracellular human pathogen, causes systemic infections with high mortality rate. The majority of the known pathogenicity factors of L. monocytogenes is regulated by a single transcription factor, PrfA. Hyperhaemolytic laboratory strains of L. monocytogenes express the constitutively active mutant PrfA(G145S) inducing virulence gene overexpression independent of environmental conditions. PrfA belongs to the Crp/Fnr family of transcription factors generally activated by a small effector, such as cAMP or O(2). We present the crystal structures of wild-type PrfA, the first Gram-positive member of the Crp/Fnr family, and of the constitutively active mutant PrfA(G145S). Cap (Crp) has previously been described exclusively in the cAMP-induced (DNA-free and -bound) conformation. By contrast, the PrfA structures present views both of the non-induced state and of the mutationally activated form. The low DNA-binding affinity of wild-type PrfA is supported both structurally (partly disordered helix-turn-helix motif, overall geometry of the HTH alpha-helices deviates from Cap) and by surface plasmon resonance analyses (K(D) = 0.9 microM). In PrfA(G145S) the HTH motifs dramatically rearrange to adopt a conformation comparable to cAMP-induced Cap and hence favourable for DNA binding, supported by a DNA-binding affinity of 50 nM. Finally, the hypothesis that wild-type PrfA, like other Crp/Fnr family members, may require an as yet unidentified cofactor for activation is supported by the presence of a distinct tunnel in PrfA, located at the interface of the beta-barrel and the DNA-binding domain.

PubMed: 15813735
DOI: 10.1111/J.1365-2958.2005.04561.X

Experimental method

X-RAY DIFFRACTION (2.3 Å)