SELECTIVE AMPLIFICATION OF DNA FRAGMENTS CODING FOR THE G-DOMAIN OF FACTORS IF2 AND EF-TU, 2 G-PROTEINS FROM THE MYXOBACTERIUM STIGMATELLA-AURANTIACA

Two DNA fragments of the genome of the myxobacterium Stigmatella auran tiaca were selectively amplified by PCR. These fragments encode a segm ent of the G domain of translational initiation factor IF2 and elongat ion factor EF-Tu, two CTP-blnding proteins. This was made possible by carefully designing the primers for this reaction to avoid the amplifi cation of every G-domain-encoding region of the genome. The sequence o f two pairs of primers was deduced from highly conserved regions, name ly G(1) and G(3) and/or their vicinal amino acids, within each subfami ly (Initiation and elongation factors, respectively) of GTP-binding pr oteins. On the basis of the expected size, one band was selected in ea ch experiment cloned into a vector, and sequenced. This showed unambig uously after comparison analysis that they belong to the IF2 and EF-Tu genes, respectively. This strategy seems suitable for the amplificati on of a segment of any gene coding for a C protein from any origin.