PHOSPHORYLATION CATALYZED BY PHOSPHODOXIN 231 



CONCLUSIONS 



Photosynthetic bacteria contain a water-soluble, heat- stable factor 

 (phosphodoxin) which stimulates photosynthetic phosphorylation by both 

 chromatophores and spinach chloroplasts. Spinach chloroplasts contain 

 a similar factor which stimulates photosynthetic phosphorylation by 

 bacterial chromatophores. The stimulated reaction by bacterial chro- 

 matophores is linear with time, bacteriochlorophy 11, and light intensity. 

 Anaerobic conditions do not affect the stimulated reaction during 

 short illumination periods, 



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