ABCMdb

ABCC8 p.Lys242Glu

Predicted by SNAP2:	A: D (71%), C: D (71%), D: D (91%), E: D (85%), F: D (85%), G: D (80%), H: D (66%), I: D (75%), L: D (80%), M: D (75%), N: D (75%), P: D (91%), Q: D (63%), R: N (87%), S: D (66%), T: N (57%), V: D (71%), W: D (80%), Y: D (80%),
Predicted by PROVEAN:	A: D, C: D, D: D, E: D, F: D, G: D, H: D, I: D, L: D, M: D, N: D, P: D, Q: D, R: N, S: D, T: D, V: D, W: D, Y: D,

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Publications
[hide] Site-directed mutagenesis of residues 164, 170, 17... Protein Eng. 1999 Apr;12(4):313-8. Bouthors AT, Delettre J, Mugnier P, Jarlier V, Sougakoff W
Site-directed mutagenesis of residues 164, 170, 171, 179, 220, 237 and 242 in PER-1 beta-lactamase hydrolysing expanded-spectrum cephalosporins.
Protein Eng. 1999 Apr;12(4):313-8., [PMID:10325401]

Abstract [show]
The class A beta-lactamase PER-1, which displays 26% identity with the TEM-type extended-spectrum beta-lactamases (ESBLs), is characterized by a substrate profile similar to that conferred by these latter enzymes. The role of residues Ala164, His170, Ala171, Asn179, Arg220, Thr237 and Lys242, found in PER-1, was assessed by site-directed mutagenesis. Replacement of Ala164 by Arg yielded an enzyme with no detectable beta-lactamase activity. Two other mutants, N179D and A164R+N179D, were also inactive. Conversely, a mutant with the A171E substitution displayed a substrate profile very similar to that of the wild-type enzyme. Moreover, the replacement of Ala171 by Glu in the A164R enzyme yielded a double mutant which was active, suggesting that Glu171 could compensate for the deleterious effect of Arg164 in the A164R+A171E enzyme. A specific increase in kcat for cefotaxime was observed with H170N, whereas R220L and T237A displayed a specific decrease in activity towards the same drug and a general increase in affinity towards cephalosporins. Finally, the K242E mutant displayed a kinetic behaviour very similar to that of PER-1. Based on three-dimensional models generated by homology modelling and molecular dynamics, these results suggest novel structure-activity relationships in PER-1, when compared with those previously described for the TEM-type ESBLs.

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No. Sentence Comment
7 Finally, the K242E mutant displayed a kinetic behaviour very similar to that of PER-1. Login to comment
72 Conversely, the pI values found for the R220L, A171E and K242E mutants were shifted towards more acidic values (pI ϭ 5.2, 5.0 and 4.9, respectively) (data not shown). Login to comment
106 Mutant K242E. Login to comment
108 Kinetic parametersa for hydrolysis of β-lactam antibiotics by PER-1 and the corresponding mutants Enzyme Penicillin G Cephalothin Cefotaxime Ceftazidime Aztreonam Km kcat kcat/Km Km kcat kcat/Km Km kcat kcat/Km Km kcat kcat/Km Km kcat kcat/Km PER-1 27 8 296 23 8 348 441 41 93 4150 109 26 147 11 75 Ϯ 3 Ϯ 0.2 Ϯ 22 Ϯ 1 Ϯ 0.1 Ϯ 17 Ϯ 42 Ϯ 2 Ϯ 8 Ϯ 611 Ϯ 15 Ϯ 8 Ϯ 15 Ϯ 0.7 Ϯ 15 A164R ND b ND ND ND ND ND ND ND ND ND ND ND ND ND ND A171E 49 9 184 47 14 298 284 39 137 4309 134 31 42 5 119 Ϯ 2 Ϯ 0.2 Ϯ 13 Ϯ 2 Ϯ 0.2 Ϯ 20 Ϯ 6 Ϯ 0.4 Ϯ 4 Ϯ 95 Ϯ 3 Ϯ 1 Ϯ 1 Ϯ 0.1 Ϯ 5 N179D ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND A164RϩA171E 23 9 391 27 12 444 300 61 203 2087 123 59 45 15 333 Ϯ 0.01 Ϯ 0.01 Ϯ 0.2 Ϯ 1 Ϯ 0.2 Ϯ 25 Ϯ 19 Ϯ 2 Ϯ 20 Ϯ 207 Ϯ 10 Ϯ 11 Ϯ 4 Ϯ 0.5 Ϯ39 A164RϩN179D ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND H170N 15 4 266 10 4 400 1286 225 175 4051 150 37 78 14 179 Ϯ 0.7 Ϯ 0.04 Ϯ 15 Ϯ 0.4 Ϯ 0.05 Ϯ 9 Ϯ 85 Ϯ 11 Ϯ 8 Ϯ 616 Ϯ19 Ϯ 10 Ϯ 9 Ϯ 1 Ϯ19 R220L 15 10 666 10 4 400 167 13 78 1329 83 62 39 6 154 Ϯ 0.4 Ϯ 0.06 Ϯ 47 Ϯ 0.3 Ϯ 0.03 Ϯ 14 Ϯ 8 Ϯ 0.3 Ϯ 5 Ϯ 33 Ϯ 1 Ϯ3 Ϯ 3 Ϯ 0.1 Ϯ14 T237A 22 11 500 7 15 2143 10 10 1000 2181 678 311 14 18 1286 Ϯ 0.4 Ϯ 0.05 Ϯ 11 Ϯ 0.3 Ϯ 0.1 Ϯ 117 Ϯ 0.7 Ϯ 0.2 Ϯ 94 Ϯ 232 Ϯ 56 Ϯ 59 Ϯ 1 Ϯ 0.2 Ϯ 110 K242E 34 8 235 36 12 333 873 94 108 3672 147 40 104 16 154 Ϯ 0.5 Ϯ 0.03 Ϯ 4 Ϯ 0.6 Ϯ 0.06 Ϯ 7 Ϯ 0.7 Ϯ 0.05 Ϯ 0.1 Ϯ 31 Ϯ 1 Ϯ 0.6 Ϯ 5 Ϯ 0.4 Ϯ 11 aUnits for Km, kcat and kcat/Km are µM, s-1 and s-1.mM-1, respectively. Login to comment
117 As shown in Table II, the steady-state kinetic parameters determined from the K242E mutant were nearly identical with those measured from PER-1. Login to comment