5u7n
From Proteopedia
CRYSTAL STRUCTURE OF A CHIMERIC CUA DOMAIN (SUBUNIT II) OF CYTOCHROME BA3 FROM THERMUS THERMOPHILUS WITH THE AMICYANIN LOOP
Structural highlights
FunctionCOX2_THET8 Subunits I and II form the functional core of the enzyme complex. Electrons originating in cytochrome c are transferred via heme a and Cu(A) to the binuclear center formed by heme a3 and Cu(B). Publication Abstract from PubMedCopper sites in proteins are designed to perform either electron transfer or redox catalysis. Type 1 and CuA sites are electron transfer hubs bound to a rigid protein fold that prevents binding of exogenous ligands and side reactions. Here we report the engineering of two Type 1 sites by loop-directed mutagenesis within a CuA scaffold with unique electronic structures and functional features. A copper-thioether axial bond shorter than the copper-thiolate bond is responsible for the electronic structure features, in contrast to all other natural or chimeric sites where the copper thiolate bond is short. These sites display highly unusual features, such as: (1) a high reduction potential despite a strong interaction with the axial ligand, which we attribute to changes in the hydrogen bond network and (2) the ability to bind exogenous ligands such as imidazole and azide. This strategy widens the possibility of using natural protein scaffolds with functional features not present in nature. Engineering a bifunctional copper site in the cupredoxin fold by loop-directed mutagenesis.,Espinoza-Cara A, Zitare U, Alvarez-Paggi D, Klinke S, Otero LH, Murgida DH, Vila AJ Chem Sci. 2018 Jun 28;9(32):6692-6702. doi: 10.1039/c8sc01444b. eCollection 2018 , Aug 28. PMID:30310603[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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