1imj

From Proteopedia

CRYSTAL STRUCTURE OF THE HUMAN CCG1/TAFII250-INTERACTING FACTOR B (CIB)

Overview

The general transcription initiation factor TFIID and its interactors play critical roles in regulating the transcription from both naked and chromatin DNA. We have isolated a novel TFIID interactor that we denoted as CCG1/TAF(II)250-interacting factor B (CIB). We show here that CIB activates transcription. To further understand the function of this protein, we determined its crystal structure at 2.2-Angstroms resolution. The tertiary structure of CIB reveals an alpha/beta-hydrolase fold that resembles structures in the prokaryotic alpha/beta-hydrolase family proteins. It is not similar in structure or primary sequence to any eukaryotic transcription or chromatin factors that have been reported to date. CIB possesses a conserved catalytic triad that is found in other alpha/beta-hydrolases, and our in vitro studies confirmed that it bears hydrolase activity. However, CIB differs from other alpha/beta-hydrolases in that it lacks a binding site excursion, which facilitates the substrate selectivity of the other alpha/beta-hydrolases. Further functional characterization of CIB based on its tertiary structure and through biochemical studies may provide novel insights into the mechanisms that regulate eukaryotic transcription.

About this Structure

1IMJ is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference

The crystal structure of CCG1/TAF(II)250-interacting factor B (CIB)., Padmanabhan B, Kuzuhara T, Adachi N, Horikoshi M, J Biol Chem. 2004 Mar 5;279(10):9615-24. Epub 2003 Dec 11. PMID:14672934

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