The double mutation ΔL6MW241F in PsbO, the photosystem II manganese stabilizing protein, yields insights into the evolution of its structure and function.
The W241F mutation in spinach manganese-stabilizing protein (PsbO) decreases binding to photosystem II (PSII); its thermostability is increased and reconstituted activity is lower [Wyman et al. (2008) Biochemistry 47, 6490-6498]. The results reported here show that W241F cannot adopt a normal solution structure and fails to reconstitute efficient Cl(-) retention by PSII. An N-terminal truncation of W241F, producing the ΔL6MW241F double mutant that resembles some features of cyanobacterial PsbO, significantly repairs the defects in W241F. Our data suggest that the C-terminal F→W mutation likely evolved in higher plants and green algae in order to preserve proper PsbO folding and PSII binding and assembly, which promotes efficient Cl(-) retention in the oxygen-evolving complex.
Popelkova
Hana
H
Department of Molecular, Cellular and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109, USA. popelka@umich.edu
Commet
Alan
A
Yocum
Charles F
CF
D000595:Amino Acid Sequence; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010649:Phenylalanine / Q000737:chemistry / Q000235:genetics; D045332:Photosystem II Protein Complex / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011487:Protein Conformation; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D018724:Spinacia oleracea / Q000201:enzymology*; D014364:Tryptophan / Q000737:chemistry / Q000235:genetics
D045332:Photosystem II Protein Complex; C054266:photosystem II manganese-stabilizing protein; D010649:Phenylalanine; D014364:Tryptophan