Growth of Synechococcus elongatus PCC 7942 under iron deficient condition leads to the accumulation of a 34 kD protein called MapA (Membrane associated protein A). This investigation includes the expression of MapA in E. coli M15. To avoid the formation of insoluble protein, when expressed in E. coli, the primers for amplification of mapA were chosen in the nucleotide sequence which has been predicted not containing the region encoding the hydrophobic part of the MapA protein. The amplified 640 bp fragment from mapA was cloned in vector pQE32 (ampicillin resistance). The clone was transformed into E. coli strain M15 which containing pREP4 kanamycin resistance. MapA protein showed overexpression in E coli and then purified. This investigation could be considered as an initiative work for expression of membrane-associated proteins in E. coli cytoplasm facilitating its purification.
Key words: Synechococcus elongatus, E. coli, membrane associated protein, overexpression
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