title: POSTTRANSLATIONAL ASSEMBLY OF PHOTOSYNTHETIC METALLOPROTEINS.
abstract: The assembly of chloroplast metalloproteins requires biochemical catalysis. Assembly factors involved in the biosynthesis of metalloproteins might be required to synthesize, chaperone, or transport the cofactor; modify or chaperone the apoprotein; or catalyze cofactor-protein association. Genetic and biochemical approaches have been applied to the study of the assembly of chloroplast iron-sulfur centers, cytochromes, plastocyanin, and the manganese center of photosystem II. These have led to the discovery of NifS-homologues and cysteine desulfhydrase for iron-sulfur center assembly, six loci (CCS1-CCS5, ccsA) for c-type cytochrome assembly, four loci for cytochrome b6 assembly (CCB1-CCB4), the CtpA protease, which is involved in pre-D1 processing, and the PCY2 locus, which is involved in holoplastocyanin accumulation. New assembly factors are likely to be discovered via the study of assembly-defective mutants of Arabidopsis, cyanobacteria, Chlamydomonas, maize, and via the functional analysis of candidate cofactor metabolizing components identified in the genome databases.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569; e-mail: merchant@chem.ucla.edu; bdreyfus@ucla.edu
authors.forename: Sabeeha
authors.initials: S
authors.lastname: Merchant
authors.forename: Beth Welty
authors.initials: BW
authors.lastname: Dreyfuss