Cesira de Chiara*, Gareth A. Prosser, Roksana Ogrodowicz and Luiz P. S. de Carvalho*,
{"title":"Structure of the d-Cycloserine-Resistant Variant D322N of Alanine Racemase from Mycobacterium tuberculosis","authors":"Cesira de Chiara*, Gareth A. Prosser, Roksana Ogrodowicz and Luiz P. S. de Carvalho*, ","doi":"10.1021/acsbiomedchemau.2c00074","DOIUrl":null,"url":null,"abstract":"<p >Alanine racemase (Alr) is a pyridoxal 5′-phosphate-dependent enzyme that catalyzes the racemization of <span>l</span>-alanine to <span>d</span>-alanine. Alr is one of the two targets of the broad-spectrum antibiotic <span>d</span>-cycloserine (DCS), a structural analogue of <span>d</span>-alanine. Despite being an essential component of regimens used to treat multi- and extensively drug-resistant tuberculosis for almost seven decades, resistance to DCS has not been observed in patients. We previously demonstrated that DCS evades resistance due to an ultralow rate of emergence of mutations. Yet, we identified a single polymorphism (converting Asp322 to Asn) in the <i>alr</i> gene, which arose in 8 out of 11 independent variants identified and that confers resistance. Here, we present the crystal structure of the Alr variant D322N in both the free and DCS-inactivated forms and the characterization of its DCS inactivation mechanism by UV–visible and fluorescence spectroscopy. Comparison of these results with those obtained with wild-type Alr reveals the structural basis of the 240-fold reduced inhibition observed in Alr D322N.</p>","PeriodicalId":29802,"journal":{"name":"ACS Bio & Med Chem Au","volume":"3 3","pages":"233–239"},"PeriodicalIF":3.8000,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.acs.org/doi/epdf/10.1021/acsbiomedchemau.2c00074","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Bio & Med Chem Au","FirstCategoryId":"1085","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acsbiomedchemau.2c00074","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Alanine racemase (Alr) is a pyridoxal 5′-phosphate-dependent enzyme that catalyzes the racemization of l-alanine to d-alanine. Alr is one of the two targets of the broad-spectrum antibiotic d-cycloserine (DCS), a structural analogue of d-alanine. Despite being an essential component of regimens used to treat multi- and extensively drug-resistant tuberculosis for almost seven decades, resistance to DCS has not been observed in patients. We previously demonstrated that DCS evades resistance due to an ultralow rate of emergence of mutations. Yet, we identified a single polymorphism (converting Asp322 to Asn) in the alr gene, which arose in 8 out of 11 independent variants identified and that confers resistance. Here, we present the crystal structure of the Alr variant D322N in both the free and DCS-inactivated forms and the characterization of its DCS inactivation mechanism by UV–visible and fluorescence spectroscopy. Comparison of these results with those obtained with wild-type Alr reveals the structural basis of the 240-fold reduced inhibition observed in Alr D322N.
期刊介绍：
ACS Bio & Med Chem Au is a broad scope open access journal which publishes short letters comprehensive articles reviews and perspectives in all aspects of biological and medicinal chemistry. Studies providing fundamental insights or describing novel syntheses as well as clinical or other applications-based work are welcomed.This broad scope includes experimental and theoretical studies on the chemical physical mechanistic and/or structural basis of biological or cell function in all domains of life. It encompasses the fields of chemical biology synthetic biology disease biology cell biology agriculture and food natural products research nucleic acid biology neuroscience structural biology and biophysics.The journal publishes studies that pertain to a broad range of medicinal chemistry including compound design and optimization biological evaluation molecular mechanistic understanding of drug delivery and drug delivery systems imaging agents and pharmacology and translational science of both small and large bioactive molecules. Novel computational cheminformatics and structural studies for the identification (or structure-activity relationship analysis) of bioactive molecules ligands and their targets are also welcome. The journal will consider computational studies applying established computational methods but only in combination with novel and original experimental data (e.g. in cases where new compounds have been designed and tested).Also included in the scope of the journal are articles relating to infectious diseases research on pathogens host-pathogen interactions therapeutics diagnostics vaccines drug-delivery systems and other biomedical technology development pertaining to infectious diseases.
京公网安备 11010802042870号
京ICP备2023020795号-1
分享
求助内容：
应助结果提醒方式：
扫码关注我们
