2riq

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spinqualitylabelsall models PDB ID 2riq Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
, resolution 1.70Å
Sites:	, , , and
Ligands:	, and
Gene:	PARP1, ADPRT, PPOL (Homo sapiens)
Activity:	NAD(+) ADP-ribosyltransferase, with EC number 2.4.2.30
Coordinates:	save as pdb, mmCIF, xml

Crystal Structure of the Third Zinc-binding domain of human PARP-1

Overview

Poly(ADP-ribose) polymerase-1 (PARP-1) is a chromatin-associated enzyme with multiple cellular functions, including DNA repair, transcriptional regulation, and cell signaling. PARP-1 has a modular architecture with six independent domains comprising the 113-kDa polypeptide. Two zinc finger domains at the N terminus of PARP-1 bind to DNA and thereby activate the catalytic domain situated at the C terminus of the enzyme. The tight coupling of DNA binding and catalytic activities is critical to the cellular regulation of PARP-1 function; however, the mechanism for coordinating these activities remains an unsolved problem. Here, we demonstrate using spectroscopic and crystallographic analysis that human PARP-1 has a third zinc-binding domain. Biochemical mutagenesis and deletion analysis indicate that this region mediates interdomain contacts important for DNA-dependent enzyme activation. The crystal structure of the third zinc-binding domain reveals a zinc ribbon fold and suggests conserved residues that could form interdomain contacts. The new zinc-binding domain self-associates in the crystal lattice to form a homodimer with a head-totail arrangement. The structure of the homodimer provides a scaffold for assembling the activated state of PARP-1 and suggests a mechanism for coupling the DNA binding and catalytic functions of PARP-1.

About this Structure

2RIQ is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.

Reference

A Third Zinc-binding Domain of Human Poly(ADP-ribose) Polymerase-1 Coordinates DNA-dependent Enzyme Activation., Langelier MF, Servent KM, Rogers EE, Pascal JM, J Biol Chem. 2008 Feb 15;283(7):4105-14. Epub 2007 Nov 30. PMID:18055453

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