Third BIR domain of XIAP binds to both Cu(II) and Cu(I) in multiple sites and with diverse affinities characterized at atomic resolution.

ABSTRACT: The X-chromosome linked inhibitor of apoptosis, XIAP, is mainly known as the inhibitor of caspases by direct interaction with caspases with its baculoviral IAP repeat (BIR) domains. XIAP has three BIR domains and each BIR domain contains a zinc binding site, normally known as zinc finger motif. Recent studies showed that XIAP is involved in copper homeostasis in cells and the BIR domains bind copper ion. However, structural details of the second and third BIR domain, BIR2 and BIR3, in XIAP, with copper as well as the binding modes are not known. In the present work we characterize the structural properties of BIR3 in solution by high resolution NMR and other biophysical techniques. The interaction of BIR3 with copper both in vitro and in cell lysates was analyzed. Our results show that BIR

SUBMITTER: Chen SN 

PROVIDER: S-EPMC6520397 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature