SNAP annotations: PDB entry 1hbx

PDB-id

1hbx; DSSR-derived features in text and JSON formats; DNAproDB

Class

gene regulation

Method

X-ray (3.15 Å)

Summary

Ternary complex of sap-1 and srf with specific sre DNA

Reference

Hassler M, Richmond TJ (2001): "The B-Box Dominates Sap-1/Srf Interactions in the Structure of the Ternary Complex." Embo J., 20, 3018. doi: 10.1093/EMBOJ/20.12.3018.

Abstract

The serum response element (SRE) is found in several immediate-early gene promoters. This DNA sequence is necessary and sufficient for rapid transcriptional induction of the human c-fos proto-oncogene in response to stimuli external to the cell. Full activation of the SRE requires the cooperative binding of a ternary complex factor (TCF) and serum response factor (SRF) to their specific DNA sites. The X-ray structure of the human SAP-1-SRF-SRE DNA ternary complex was determined (Protein Data Bank code 1hbx). It shows SAP-1 TCF bound to SRF through interactions between the SAP-1 B-box and SRF MADS domain in addition to contacts between their respective DNA-binding motifs. The SAP-1 B-box is part of a flexible linker of which 21 amino acids become ordered upon ternary complex formation. Comparison with a similar region from the yeast MATalpha2-MCM1-DNA complex suggests a common binding motif through which MADS-box proteins may interact with additional factors such as Fli-1.