Purification and characterization of E37, a major chloroplast envelope protein

We have purified to homogeneity E37, the second major polypeptide of the inner membrane of the chloroplast envelope. The protein was retained on a Mono S column at pH 7, indicating it is a basic protein. After cyanogen cleavage, the protein was partially sequenced at 2 different sites. The sequence is compared with the deduced amino acid sequence of a cDNA coding for a 37 kDa envelope polypeptide recently published by Dreses-Werringloer et al. (Eur. J. Biochem. (1991) 195, 361-368.)