“…PCC 6803. Cysteines 14 and 51 were changed to alanine (C14A PsaC , C51A PsaC ), aspartic acid (C14D PsaC , C51D PsaC ), and serine (C14S PsaC , C51S PsaC ), and the results were compared with in vitro reconstitution studies (3,4,36). In each instance, the PsaC mutant strains could not grow under standard photoautotrophic growth conditions, but could grow mixotrophically under weak light, indicating a light-sensitive lesion in PS I that had become limiting for growth.…”