1K9K

CRYSTAL STRUCTURE OF CALCIUM BOUND HUMAN S100A6

Summary for 1K9K

• Entry DOI: 10.2210/pdb1k9k/pdb
• Related: 1K8U 1K96 1K9P
• Descriptor: S100A6, CALCIUM ION, BETA-MERCAPTOETHANOL, ... (4 entities in total)
• Functional Keywords: s100a6, calcyclin, calcium regulatory protein, calcium bound, cacy, signaling protein
• Biological source: Homo sapiens (human)
• Cellular location: Nucleus envelope: P06703
• Total number of polymer chains: 2
• Total formula weight: 20704.04

Authors

Otterbein, L.R.,Dominguez, R. (deposition date: 2001-10-29, release date: 2002-04-10, Last modification date: 2023-08-16)

Primary citation

Otterbein, L.R.,Kordowska, J.,Witte-Hoffmann, C.,Wang, C.L.,Dominguez, R.
Crystal structures of S100A6 in the Ca(2+)-free and Ca(2+)-bound states: the calcium sensor mechanism of S100 proteins revealed at atomic resolution.
Structure, 10:557-567, 2002

PubMed Abstract: S100A6 is a member of the S100 family of Ca(2+) binding proteins, which have come to play an important role in the diagnosis of cancer due to their overexpression in various tumor cells. We have determined the crystal structures of human S100A6 in the Ca(2+)-free and Ca(2+)-bound states to resolutions of 1.15 A and 1.44 A, respectively. Ca(2+) binding is responsible for a dramatic change in the global shape and charge distribution of the S100A6 dimer, leading to the exposure of two symmetrically positioned target binding sites. The results are consistent with S100A6, and most likely other S100 proteins, functioning as Ca(2+) sensors in a way analogous to the prototypical sensors calmodulin and troponin C. The structures have important implications for our understanding of target binding and cooperativity of Ca(2+) binding in the S100 family.

PubMed: 11937060
DOI: 10.1016/S0969-2126(02)00740-2

Experimental method

X-RAY DIFFRACTION (1.76 Å)