CARTOGRAPHY OF RIBOSOMAL-PROTEINS OF THE 30S SUBUNIT FROM THE HALOPHILIC HALOARCULA-MARISMORTUI AND COMPLETE SEQUENCE-ANALYSIS OF PROTEIN HS26

By two-dimensional polyacrylamide gel electrophoresis of 30S ribosomal subunit proteins (S proteins) from Haloarcula marismortui we identifi ed 27 distinct spots and analyzed all of them by protein sequence anal ysis. We demonstrated that protein HmaS2 (HS2) is encoded by the open reading frame orfMSG and has sequence similarities to the S2 ribosomal protein family. The proteins HmaS5 and HmaS14 were identified as spot s HS7 and HS21/HS22, respectively. Protein HS4 was characterized by am ino-terminal sequence analysis. The spot HS25 was recognized as an ind ividual protein and also characterized by sequence analysis. Furthermo re, the complete primary sequence of HS26 is reported, showing similar ity only to eukaryotic ribosomal proteins. The sequence data of a furt her basic protein shows a high degree of similarity to ribosomal prote in S12, therefore it was designated HmaS12. Slightly different results compared to published sequence data were obtained for the proteins HS 12 and HmaS19. The putative 'ribosomal' protein HSH could not be local ized in the two-dimensional pattern of the total 30S ribosomal subunit proteins of H. marismortui. Therefore, it seems to be unlikely that t his protein is a real constituent of the H. marismortui, ribosome.