Journal:

Article Title: Multiple Mutations Modulate the Function of Dihydrofolate Reductase in Trimethoprim-Resistant Streptococcus pneumoniae

doi: 10.1128/AAC.45.4.1104-1108.2001

Figure Lengend Snippet: Amino acid sequence changes and DHFR characteristics of selected CP1015 transformants

Article Snippet: One transformant of R12 (T2) contained only the D92-A and I100-L mutations and required 128 mg of trimethoprim per liter for inhibition of growth, 1 dilution lower than that of the donor isolate. table ft1 table-wrap mode="anchored" t5 TABLE 3 caption a7 Isolate Amino acid at position a : MIC (mg/liter) IC 50 (μM) K m (μM) b Specificity constant c 14 16 20 26 53 * 60 70 74 78 81 91 92 94 100 * † 120 135 147 149 DHF NADPH ATCC 49619 V 4 0.05 3.9 (0.83) 17.8 (4.4) 0.024 CP1015 E L E H M K P I A Q Q D E I H L F A 4 0.09 3.1 (0.48) 18.2 (3.2) 0.014 720/T1 D V D S L H H A D L F S T 512 2.9 9.2 (3.3) 30.7 (7.9) 0.09 720/T2 V D S L H H A D L 256 1.4 12.6 (3.3) 21.9 (5.2) 0.04 1802/T1 V D Y I Q S T A L Q F S T 512 13.7 14.3 (2.3) 29.0 (4.4) 0.026 1802/T2 V D Y I Q S T A L 512 10.1 24.1 (8.6) 52.7 (23.7) 0.007 R12/T1 T A L Q F S T 256 2.1 15.2 (2.8) 20.3 (4.7) 0.016 R12/T2 A L 128 4.2 27.7 (9.7) 35.1 (11.4) 0.0063 Open in a separate window a *, trimethoprim binding site in the DHFR of E. coli K-12; †, NADPH binding site in the DHFR of E. coli K-12 (as reported by Dale et al. [ 4 , 5 ]). b Values in parentheses are standard errors. c V max / K m (μM).

Techniques: Sequencing