Why is it so difficult to construct Q(i) site mutants in Chlamydomonas reinhardtii?
The cytochrome b(6)f complex catalyses electron transfer from plastoquinol to a hydrosoluble acceptor (plastocyanin), while building up an electrochemical proton gradient. Oxidation and reduction of plastoquinol occur respectively at the Q(o) site (exposed on the luminal side of the thylakoid membrane) and at the Q(i) site (facing the stroma). The discovery of an additional c'-type heme in the Q(i) site has cast a new light on the difficulties previously encountered to obtain mutants at this site. In this work, we critically examine our unsuccessful attempts to obtain Q(i) site mutants based on sequence and structure homology between cytochrome b(6)f and bc(1) complexes.
UMR 7099, CNRS and Université Paris-7, Institut de Biologie Physico-Chimique, Paris, France.
Agnès
A
de Lacroix de Lavalette
Romina Paola
RP
Barbagallo
Francesca
F
Zito
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D016825:Chlamydomonas reinhardtii / Q000235:genetics*; D002736:Chloroplasts / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D003580:Cytochromes / Q000737:chemistry / Q000235:genetics*; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011487:Protein Conformation
D003580:Cytochromes