Webber A N, Malkin R
Department of Plant Biology, University of California, Berkeley 94720.
FEBS Lett. 1990 May 7;264(1):1-4. doi: 10.1016/0014-5793(90)80749-9.
The photosystem I (PS I) reaction-centre polypeptides, encoded by the psaA and psaB genes, are shown to contain several highly conserved leucine repeats, consisting of a leucine residue every seventh amino acid, similar to the leucine zipper motifs known to mediate DNA-binding polypeptide dimerisation. In each of the PSI reaction-centre subunits the leucine zipper motif precedes highly conserved cysteine residues which have been proposed to ligate the interpolypeptide [4Fe-4S] centre, Fx. We propose that PS I reaction-centre dimerisation and [4Fe-4S] centre formation are mediated through the leucine zipper.
由psaA和psaB基因编码的光系统I（PS I）反应中心多肽显示含有几个高度保守的亮氨酸重复序列，每七个氨基酸就有一个亮氨酸残基，类似于已知介导DNA结合多肽二聚化的亮氨酸拉链基序。在每个PSI反应中心亚基中，亮氨酸拉链基序位于高度保守的半胱氨酸残基之前，有人提出这些半胱氨酸残基用于连接多肽间的[4Fe-4S]中心Fx。我们认为PSI反应中心的二聚化和[4Fe-4S]中心的形成是通过亮氨酸拉链介导的。
