For the record: Temperature‐sensitive suppressor mutations of the <i>Escherichia coli</i> DNA gyrase B protein

Blance, Stephen J; Williams, Nicola L.; Preston, Zoë A.; Bishara, John; Smyth, Michael; Maxwell, Anthony

doi:10.1110/ps.9.5.1035

Cited by 14 publications

(13 citation statements)

References 17 publications

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“…hydrophobic interactions by second-site mutations were also reported previously in E. coli DNA gyrase and phospholipase A2 (PLA2) (Blance et al, 2000;Sekharudu et al, 1992). The second-site substitution of Thr57 with isoleucine in E. coli DNA gyrase could compensate for the G164V mutation-induced loss of stability by making new hydrophobic interactions with Val156 and Ile140 (Blance et al, 2000).…”

Section: A B a B A Bsupporting

confidence: 60%

“…The second-site substitution of Thr57 with isoleucine in E. coli DNA gyrase could compensate for the G164V mutation-induced loss of stability by making new hydrophobic interactions with Val156 and Ile140 (Blance et al, 2000). The Y52F/Y73F PLA2 double mutant structural studies demonstrated that the increased phenyl group hydrophobic interactions compensated for the loss of tyrosine residue hydrogen bonds (Sekharudu et al, 1992).…”

Section: A B a B A Bmentioning

confidence: 99%

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Rescue of Deleterious Mutations by the Compensatory Y30F Mutation in Ketosteroid Isomerase

Jin

Jang

Kim

et al. 2013

Molecules and Cells

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Proteins have evolved to compensate for detrimental mutations. However, compensatory mechanisms for protein defects are not well understood. Using ketosteroid isomerase (KSI), we investigated how second-site mutations could recover defective mutant function and stability. Previous results revealed that the Y30F mutation rescued the Y14F, Y55F and Y14F/Y55F mutants by increasing the catalytic activity by 23-, 3-and 1.3-fold, respectively, and the Y55F mutant by increasing the stability by 3.3 kcal/mol. To better understand these observations, we systematically investigated detailed structural and thermodynamic effects of the Y30F mutation on these mutants. Crystal structures of the Y14F/Y30F and Y14F/Y55F mutants were solved at 2.0 and 1.8 Å resolution, respectively, and compared with previoulsy solved structures of wild-type and other mutant KSIs. Structural analyses revealed that the Y30F mutation partially restored the active-site cleft of these mutant KSIs. The Y30F mutation also increased Y14F and Y14F/Y55F mutant stability by 3.2 and 4.3 kcal/mol, respectively, and the melting temperatures of the Y14F, Y55F and Y14F/Y55F mutants by 6.4°C, 5.1°C and 10.0°C, respectively. Compensatory effects of the Y30F mutation on stability might be due to improved hydrophobic interactions because removal of a hydroxyl group from Tyr30 induced local compaction by neighboring residue movement and enhanced interactions with surrounding hydrophobic residues in the active site. Taken together, our results suggest that perturbed active-site geometry recovery and favorable hydrophobic interactions mediate the role of Y30F as a secondsite suppressor.

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Section: A B a B A Bsupporting

confidence: 60%

Section: A B a B A Bmentioning

confidence: 99%

Rescue of Deleterious Mutations by the Compensatory Y30F Mutation in Ketosteroid Isomerase

Jin

Jang

Kim

et al. 2013

Molecules and Cells

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“…Stabilizing mutations have been shown to play a central role in the evolution of ␤-lactamases and other enzymes (5,8,15,(42)(43)(44). Amino acid substitutions in the active site of CTX-M enzymes may change their activity and substrate specificity at the cost of stability.…”

Section: Discussionmentioning

confidence: 99%

Characterization of the Global Stabilizing Substitution A77V and Its Role in the Evolution of CTX-M β-Lactamases

Patel

Fryszczyn

Palzkill

2015

Antimicrob Agents Chemother

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The widespread use of oxyimino-cephalosporin antibiotics drives the evolution of the CTX-M family of ␤-lactamases that hydrolyze these drugs and confer antibiotic resistance. Clinically isolated CTX-M enzymes carrying the P167S or D240G active siteassociated adaptive mutation have a broadened substrate profile that includes the oxyimino-cephalosporin antibiotic ceftazidime. The D240G substitution is known to reduce the stability of CTX-M-14 ␤-lactamase, and the P167S substitution is shown here to also destabilize the enzyme. Proteins are marginally stable entities, and second-site mutations that stabilize the enzyme can offset a loss in stability caused by mutations that enhance enzyme activity. Therefore, the evolution of antibiotic resistance enzymes can be dependent on the acquisition of stabilizing mutations. The A77V substitution is present in CTX-M extendedspectrum ␤-lactamases (ESBLs) from a number of clinical isolates, suggesting that it may be important in the evolution of antibiotic resistance in this family of ␤-lactamases. In this study, the effects of the A77V substitution in the CTX-M-14 model enzyme were characterized with regard to the kinetic parameters for antibiotic hydrolysis as well as enzyme expression levels in vivo and protein stability in vitro. The A77V substitution has little effect on the kinetics of oxyimino-cephalosporin hydrolysis, but it stabilizes the CTX-M enzyme and compensates for the loss of stability resulting from the P167S and D240G mutations. The acquisition of global stabilizing mutations, such as A77V, is an important feature in ␤-lactamase evolution and a common mechanism in protein evolution.T he introduction of new antibiotics into clinical use fuels the evolution of enzymes causing drug resistance. These enzymes gain the ability to inactivate antibiotics more efficiently by acquiring point mutations in and around their active sites that increase catalytic activity (1). However, the introduction of new gain-offunction mutations within highly organized active sites often comes at a stability cost to the enzymes (2-6). Therefore, enzymes can absorb only a limited number of destabilizing mutations before they unfold and lose function (7). This limitation in the evolution of catalytic efficiency is often overcome by the acquisition of global stabilizing mutations that offset the incremental loss in stability due to the primary mutation. This compensation mechanism allows the enzymes to continue a mutational trajectory, resulting in increased resistance.The role of global stabilizing mutations in enzyme evolution has been widely studied (4,8,9). In recent decades, the selection of mutant ␤-lactamase enzymes with expanded substrate specificity has occurred for the plasmid-mediated TEM-and SHV-type ␤-lactamases to give rise to extended-spectrum ␤-lactamases (ESBLs) (10, 11). These enzymes arise due to mutations resulting in substitutions near the active site that increase hydrolysis of oxyimino-cephalosporins such as cefotaxime and ceftazidime. The substitutions that increa...

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“…Reduction of the biological cost of resistance by intragenic compensation has been shown to occur in bacteria resistant to fusidic acid [51,83], streptomycin [8,9,74,102], β-lactams [50,91,104], rifampicin [8,96], sulfonamides [38] and coumarins [11]. Fusidic-acid-resistant mutants carry amino acid substitutions in elongation factor G. This results in a defect in GTP binding, a concomitant decrease in peptidyl-tRNA movement during the elongation phase of translation and slowed bacterial growth.…”

Section: Intragenic Compensation To Restore An Altered Function or Stmentioning

confidence: 99%

“…the catalytic site of the GyrB subunit, which can be relieved by two second-site mutations, H38Q or T157I, located at either end of a turn above the drug binding site [11]. The substitution T157I is thought to give a more favorable hydrophobic interaction that helps to stabilize the loop.…”

Section: Intragenic Compensation To Restore An Altered Function or Stmentioning

confidence: 99%

Adaptation to the deleterious effects of antimicrobial drug resistance mutations by compensatory evolution

Maisnier‐Patin

Andersson

2004

Research in Microbiology

227

190

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Compensatory mutations, due to their ability to mask the deleterious effects of another mutation, are important for the adaptation and evolution of most organisms. Resistance to antibiotics, antivirals, antifungals, herbicides and insecticides is usually associated with a fitness cost. As a result of compensatory evolution, the initial fitness costs conferred by resistance mutations (or other deleterious mutations) can often be rapidly and efficiently reduced. Such compensatory evolution is potentially of importance for (i) the long-term persistence of drug resistance, (ii) reducing the rate of fitness loss associated with the accumulation of deleterious mutations in small asexual populations, and (iii) the evolution of complexity of cellular processes.  2004 Elsevier SAS. All rights reserved.

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For the record: Temperature‐sensitive suppressor mutations of the Escherichia coli DNA gyrase B protein

Cited by 14 publications

References 17 publications

Rescue of Deleterious Mutations by the Compensatory Y30F Mutation in Ketosteroid Isomerase

Rescue of Deleterious Mutations by the Compensatory Y30F Mutation in Ketosteroid Isomerase

Characterization of the Global Stabilizing Substitution A77V and Its Role in the Evolution of CTX-M β-Lactamases

Adaptation to the deleterious effects of antimicrobial drug resistance mutations by compensatory evolution

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