CHM ENG 170A Midterm: cheme170-fa2004-mt1-Clark-soln

• School: Berkeley
• Department: Chemical & Biomolecular Engineering
• Course: CHM ENG 170A
• Professor: all

Document Summary

One 8. 5 x 11 in. page of notes allowed. Recently site-directed mutagenesis was used to modify the cofactor specificity of the enzyme phosphite dehydrogenase (woodyer et al. , biochemistry 2003, 42, 11604). Figure 1 on the last page are interactions between the wildtype (wt), the e175a mutant, and the e175a, a176r double mutant enzymes and the nicotinamide cofactor nadp (the 2"- phosphate of nadp is shown in red and yellow). Wt (+1: briefly explain (1-2 sentences) your answer above. E175a, a176r double mutant (+1: briefly explain (1-2 sentences) your answer above. As shown in figure 2 on the last page, the enzyme trna guanine transglycosylase (tgt) catalyzes replacement of guanine (g) by 7-aminomethyl-7-deazaguanine (preq1) at a specific position of four trnas. E trna-g e + trna-preq1) consistent with the mechanism described above. E + trna-preq1 (+6: using site-directed mutagenesis, you propose to generate two different mutant enzymes, with each mutant containing a replacement for asp in position 102.