PDBsum entry 4n9i

Transcription regulator

PDB id: 4n9i

Contents

Protein chains

202 a.a.

Ligands

PCG ×4

Waters ×268

PDB id:

4n9i

Name:

Transcription regulator

Title:

Crystal structure of transcription regulation protein crp complexed with cgmp

Structure:

Catabolite gene activator. Chain: a, b, c, d. Synonym: cyclic amp receptor protein. Engineered: yes

Source:

Escherichia coli. Organism_taxid: 562. Gene: crp, bn17_32921, ecs4208, lf82_0356. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.19Å R-factor: 0.172 R-free: 0.208

Authors:

B.-J.Lee,S.-H.Seok,H.Im,H.-J.Yoon

Key ref:

S.H.Seok et al. (2014). Structures of inactive CRP species reveal the atomic details of the allosteric transition that discriminates cyclic nucleotide second messengers. Acta Crystallogr D Biol Crystallogr, 70, 1726-1742. PubMed id: 24914983 DOI: 10.1107/S139900471400724X

Date:

21-Oct-13 Release date: 09-Jul-14

Protein chains

C3SQJ7  (C3SQJ7_ECOLX) -  Catabolite activator protein from Escherichia coli

Seq: 210 a.a.

Struc: 202 a.a.

DOI no: 10.1107/S139900471400724X

Acta Crystallogr D Biol Crystallogr 70:1726-1742 (2014)

PubMed id: 24914983

Structures of inactive CRP species reveal the atomic details of the allosteric transition that discriminates cyclic nucleotide second messengers.

S.H.Seok, H.Im, H.S.Won, M.D.Seo, Y.S.Lee, H.J.Yoon, M.J.Cha, J.Y.Park, B.J.Lee.

ABSTRACT

The prokaryotic global transcription factor CRP has been considered to be an ideal model for in-depth study of both the allostery of the protein and the differential utilization of the homologous cyclic nucleotide second messengers cAMP and cGMP. Here, atomic details from the crystal structures of two inactive CRP species, an apo form and a cGMP-bound form, in comparison with a known active conformation, the cAMP-CRP complex, provide macroscopic and microscopic insights into CRP allostery, which is coupled to specific discrimination between the two effectors. The cAMP-induced conformational transition, including dynamic fluctuations, can be driven by the fundamental folding forces that cause water-soluble globular proteins to construct an optimized hydrophobic core, including secondary-structure formation. The observed conformational asymmetries underlie a negative cooperativity in the sequential binding of cyclic nucleotides and a stepwise manner of binding with discrimination between the effector molecules. Additionally, the finding that cGMP, which is specifically recognized in a syn conformation, induces an inhibitory conformational change, rather than a null effect, on CRP supports the intriguing possibility that cGMP signalling could be widely utilized in prokaryotes, including in aggressive inhibition of CRP-like proteins.