Two partially homologous adjacent light-inducible maize chloroplast genes encoding polypeptides of the P700 chlorophyll a-protein complex of photosystem I.

EXAFS structural study of FX, the low-potential iron-sulfur center in photosystem I

“…Previous structural analyses by spectroscopic methods have been consistent with [4Fe-4S] (Evans et al, 1981) or [2Fe-2S] (Golbeck et al, 1987;McDermott et al, 1988;Bertrand et al, 1988) or a distorted [4Fe-4S] cluster (McDermott et al, 1988). Examination of the polypeptide sequences of psaA and psaB (Fish et al, 1985), which are the putative binding sites of Fx (Golbeck et al, 1988), reveals none of the characteristic sequence elements of or ferredoxins [reviewed in Stout (1982)]. A consideration of the stoichiometries of Fe, acid-labile sulfide, and cysteines per complex would argue against the presence of [2Fe-2S] clusters on the psaA and psaB polypeptides (Bruce & Malkin, 1988; 1 Abbreviations: EPR, electron paramagnetic resonance; EXAFS, extended X-ray absorption fine structure; FA, FB, and Fx, ferredoxins in photosystem I, alternatively referred to as centers A, B, and X; kDa, kilodaltons; PS I, photosystem I; psaA and psaB, reaction center polypeptides in PS I, also referred to as PSI-A1 and PSI-A2; P700, primary electron donor in PS I; Tirón, 4,5-dihydroxy-1,3-benzenedisulfonic acid; Tris, tris(hydroxymethyl)aminomethane.…”

Lawrence Bogorad's scientific contributions and remembrances on his 100th birth anniversary

“…In quick succession, the second chloroplast protein gene was mapped, which was a photoregulated gene (now designated as psbA; Bedbrook et al ., 1978 ). The discovery of psbA gene (PG32) encoding the 32 kD protein, which turned out to be the D1 reaction centre protein of Photosystem II (PSII), gave birth to the field of light‐regulated chloroplast biogenesis and light‐induced expression of photosynthetic genes (Bedbrook et al ., 1978 ; Fish et al ., 1985 ). Several photogenes were later cloned and characterized after the complete chloroplast genome sequence had become available in the mid‐1980s.…”

“…The rbcL gene was the first plant protein gene to be sequenced in Bogorad's laboratory (McIntosh et al ., 1980 ). Several other chloroplast genes encoding photosynthetic proteins were later identified based on the use of antibodies and Western blotting experiments (Fish et al ., 1985 ; Haley and Bogorad, 1989 ). Another significant contribution from Bogorad's lab was a metal ion regulation of the expression of photosynthetic proteins.…”

Molecular genetics of chloroplasts and mitochondria in the unicellular green algaChlamydomonas

“…This photosynthetic complex consists of a large number of polypeptides: two chloroplast encoded polypeptides of apparent M r 60000-70000 (subunit I) both of which appear to be the apoproteins of the CPI chlorophyll-protein complex which comprises the reaction center chlorophyll P700 [90,91], and several smaller subunits with sizes ranging between 25 and 8 kDa [92]. Recently, the two genes of subunit I, psA1 and psaA2, of C. reinhardtii have been sequenced (U. Khck, M. Schneider, M. Dron, Y. Choquet, unpublished results).…”