The protein map of Synechococcus sp. PCC 7942 - the first overlook

SUMMARY The unicellular cyanobacterium Synechococcus PCC 7942 has been used as a model organism for studies of prokaryotic circadian rhythms, carbon-concentrating mechanisms, response to a variety of nutrient and environmental stresses, and cell division. This paper presents the results of the first proteomic exploratory study of Synechococcus PCC 7942. The proteome was analyzed using two-dimensional gel electrophoresis followed by MALDI-TOF mass spectroscopy, and database searching. Of 140 analyzed protein spots, 110 were successfully identified as 62 different proteins, many of which occurred as multiple spots on the gel. The identified proteins were organized into 18 different functional categories reflecting the major metabolic and cellular processes occurring in the cyanobacterial cells in the exponential growth phase. Among the identified proteins, 14 previously unknown or considered to be hypothetical are here shown to be true gene products in Synechococcus sp. PCC 7942, and may be helpful for annotation of the newly sequenced genome.