SNAP output for PDB entry 1cgp [SNAP web server]

PDB-id

1cgp; SNAP-derived features in text and JSON formats; DNAproDB

Class

transcription-DNA

Method

X-ray (3.0 Å)

Summary

Catabolite gene activator protein (cap)-DNA complex + adenosine-3',5'-cyclic-monophosphate

Reference

Schultz SC, Shields GC, Steitz TA (1991): "Crystal structure of a CAP-DNA complex: the DNA is bent by 90 degrees." Science, 253, 1001-1007.

Abstract

The 3 angstrom resolution crystal structure of the Escherichia coli catabolite gene activator protein (CAP) complexed with a 30-base pair DNA sequence shows that the DNA is bent by 90 degrees. This bend results almost entirely from two 40 degrees kinks that occur between TG/CA base pairs at positions 5 and 6 on each side of the dyad axis of the complex. DNA sequence discrimination by CAP derives both from sequence-dependent distortion of the DNA helix and from direct hydrogen-bonding interactions between three protein side chains and the exposed edges of three base pairs in the major groove of the DNA. The structure of this transcription factor--DNA complex provides insights into possible mechanisms of transcription activation.