A CATION BINDING MOTIF STABILIZES THE COMPOUND I RADICAL OF CYTOCHROME C PEROXIDASE

X-Ray Structures of Recombinant Yeast Cytochrome C Peroxidase and Three Heme Cleft Mutants Prepared by Site-Directed Mutagenesis

Yeast Cytochrome C Peroxidase: Mutagenesis and Expression in Escherichia Coli Show Tryptophan-51 is not the Radical Site in Compound I

Crystal Structure of Yeast Cytochrome C Peroxidase Refined at 1.7 Angstroms Resolution

MIVEKLVHVASVEKGRSYEDFQKVYNAIALKLREDDEYDNYIGYGPVLVRLAWHISGTWDKHDNTGGSYGGTYRFKKEFN
DPSNAGLQNGFKFLEPIHKEFPWISSGDLFSLGGVTAVQEMQGPKIPWRCGRVDTPEDTTPDNGRLPDADKDAGYVRTFF
QRLNMNDREVVALMGAHALGKTHLKNSGYEGPQGAANNVFTNEFYLNLLNEDWKLEKNDANNEQWDSKSGYMMLPTDYSL
IQDPKYLSIVKEYANDQDKFFKDFSKAFEKLLENGITFPKDAPSPFIFKTLEEQGL

THE TRP 191 TO GLN SUBSTITUTION CREATES A SMALL CAVITY WITHIN THE ENZYME. THIS STRUCTURE HAS A SINGLE POTASSIUM ION AND TWO WATER MOLECULES BOUND IN THE CAVITY.

THIS CYTOCHROME C PEROXIDASE DIFFERS FROM A PREVIOUSLY
DEPOSITED STRUCTURE (PROTEIN DATA BANK ENTRY 2CYP) BY
TWO STRAIN-RELATED SEQUENCE DIFFERENCES - THR 53 TO ILE
AND ASP 152 TO GLY, AND THE ADDITION OF MET-ILE AT THE
N-TERMINUS, HENCE CCP(MI). THE OVERALL STRUCTURE IS THE
SAME AS THE PREVIOUSLY DEPOSITED ONE BUT IN A DIFFERENT
SPACE GROUP.

THE SEQUENCE DIFFERS FROM THAT REPORTED FOR 2CYP AT RESIDUE
272. IN THE PRESENT ENTRY, THIS RESIDUE IS REPORTED AS
ASN. THIS CORRECTS AN ERROR INTRODUCED IN 2CYP, WHERE THE
RESIDUE IS INCORRECTLY REPORTED TO BE ASP.

RESIDUES ARE NUMBERED TO BE CONSISTENT WITH THE SEQUENCE OF
THE NATIVE (2CYP) STRUCTURE. THUS THE FIRST TWO RESIDUES
HAVE RESIDUE NUMBERS -1 AND 0, RESPECTIVELY.

COORDINATES FOR RESIDUES -1, 0, AND 1 - 3 ARE NOT INCLUDED IN THIS ENTRY BECAUSE THESE RESIDUES COULD NOT BE RESOLVED IN THE FINAL ELECTRON DENSITY MAPS. WATER MOLECULES WITH B-FACTORS GREATER THAN 80 WERE NOT INCLUDED IN THE MODEL.

MTTAVRLLPSLGRTAHKRSLYLFSAAAAAAAAATFAYSQSQKRSSSSPGGGSNHGWNNWGKAAALASTTPLVHVASVEKG
RSYEDFQKVYNAIALKLREDDEYDNYIGYGPVLVRLAWHTSGTWDKHDNTGGSYGGTYRFKKEFNDPSNAGLQNGFKFLE
PIHKEFPWISSGDLFSLGGVTAVQEMQGPKIPWRCGRVDTPEDTTPDNGRLPDADKDADYVRTFFQRLNMNDREVVALMG
AHALGKTHLKNSGYEGPWGAANNVFTNEFYLNLLNEDWKLEKNDANNEQWDSKSGYMMLPTDYSLIQDPKYLSIVKEYAN
DQDKFFKDFSKAFEKLLENGITFPKDAPSPFIFKTLEEQGL