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Structural insights into the activity of enhancer-binding proteins.

ABSTRACT: Activators of bacterial sigma54-RNA polymerase holoenzyme are mechanochemical proteins that use adenosine triphosphate (ATP) hydrolysis to activate transcription. We have determined by cryogenic electron microscopy (cryo-EM) a 20 angstrom resolution structure of an activator, phage shock protein F [PspF(1-275)], which is bound to an ATP transition state analog in complex with its basal factor, sigma54. By fitting the crystal structure of PspF(1-275) at 1.75 angstroms into the EM map, we identified two loops involved in binding sigma54. Comparing enhancer-binding structures in different nucleotide states and mutational analysis led us to propose nucleotide-dependent conformational changes that free the loops for association with sigma54.

SUBMITTER: Rappas M

PROVIDER: S-EPMC2756573 | biostudies-literature | 2005 Mar

REPOSITORIES: biostudies-literature

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Structural insights into the activity of enhancer-binding proteins.

Rappas Mathieu M Schumacher Jorg J Beuron Fabienne F Niwa Hajime H Bordes Patricia P Wigneshweraraj Sivaramesh S Keetch Catherine A CA Robinson Carol V CV Buck Martin M Zhang Xiaodong X

Science (New York, N.Y.) 20050301 5717

Activators of bacterial sigma54-RNA polymerase holoenzyme are mechanochemical proteins that use adenosine triphosphate (ATP) hydrolysis to activate transcription. We have determined by cryogenic electron microscopy (cryo-EM) a 20 angstrom resolution structure of an activator, phage shock protein F [PspF(1-275)], which is bound to an ATP transition state analog in complex with its basal factor, sigma54. By fitting the crystal structure of PspF(1-275) at 1.75 angstroms into the EM map, we identifi ...[more]

PMID: 15790859

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