1LOT

CRYSTAL STRUCTURE OF THE COMPLEX OF ACTIN WITH VITAMIN D-BINDING PROTEIN

Summary for 1LOT

• Entry DOI: 10.2210/pdb1lot/pdb
• Related: 1ATN 1J6Z 1J78
• Descriptor: Vitamin D-binding protein, Actin, alpha skeletal muscle, GLYCEROL, ... (6 entities in total)
• Functional Keywords: transport protein, structural protein
• Biological source: Homo sapiens (human); More
• Cellular location: Secreted: P02774; Cytoplasm, cytoskeleton: P68135
• Total number of polymer chains: 2
• Total formula weight: 94252.74

Authors

Head, J.F.,Swamy, N.,Ray, R. (deposition date: 2002-05-07, release date: 2002-07-31, Last modification date: 2023-08-16)

Primary citation

Head, J.F.,Swamy, N.,Ray, R.
Crystal structure of the complex between actin and human vitamin D-binding protein at 2.5 A resolution.
Biochemistry, 41:9015-9020, 2002

PubMed Abstract: A high-affinity complex formed between G-actin and plasma vitamin D-binding protein (DBP) is believed to form part of a scavenging system in the plasma for removing actin released from damaged cells. In the study presented here, we describe the crystal structure of the complex between actin and human vitamin D-binding protein at 2.5 A resolution. The complex contains one molecule of each protein bound together by extensive ionic, polar, and hydrophobic interactions. It includes an ATP and a calcium ion bound to actin, but no evidence of vitamin D metabolites bound to the DBP. Both actin and DBP are multidomain molecules, two major domains in actin and three in DBP. All of these domains contribute to the interaction between the molecules. DBP enfolds the end of the actin molecule, principally in actin subdomain 3 but with additional interactions in actin subdomain 1. This orientation is similar to the binding of profilin to actin, as predicted from previous studies. The more extensive interactions of DBP give an affinity for actin some 3 orders of magnitude higher than that for profilin. The larger "footprint" of DBP on actin also leads to an overlap with the actin-binding site of gelsolin domain I.

PubMed: 12119014
DOI: 10.1021/bi026054y

Experimental method

X-RAY DIFFRACTION (2.5 Å)