133 

 MDH, respectively. MDH had about 51% similarity with the 

 SDH functional domain. These proteins did not show any 

 striking conservation of residues aligned with the SDH 

 functional domain and its homologues, except for a region 

 thought to be important for NADP"- binding. 

 Possible cDNAs coding for PAT or ADH 



Of the number of possible cDNA clones isolated with 

 specific antibodies to either PAT or ADH, no determinations 

 have been made as to whether the cDNAs of interest have been 

 cloned. The terminal regions (5' and 3') of the cDNAs that 

 were sequenced did not offer enough information. Neither 

 PAT nor ADH have been sequenced in any organism, so that 

 comparisons of homologues are not possible at present. 

 Although many aminotransferases have been cloned from plant, 

 animal and microbial species, and some very highly conserved 

 regions have been determined, they all seem to be located 

 toward the center of the genes, with very little 

 conservation at either terminus. There are no auxotrophic 

 mutants available to attempt functional complimentation for 

 these putative cDNA clones. Extract preparation and enzyme 

 assay may help to identify the correct clones if the cDNAs 

 are intact and functional. 

 Homology relationships of the DOT domain 



A multiple alignment is shown in Fig. 7-6 of the AroD 

 functional domain of the S-protein (denoted Nta-AroD»E) with 

 its homologues. The corresponding dendrogram is shown in 



