Cytochrome P450 monooxygenases are versatile biocatalysts that incorporate oxygen into an enormous range of molecules. The cytochrome P450 proteins are involved in the catalysis of different reactions and these properties have been used for drug improvement. The protein family also includes compounds producing properties such as resistance to insecticides, and the synthesis of valuable chemicals. In this review, we will discuss various aspects of the structure and function of the cytochrome P450s

 The increased prevalence of hypervirulent ribotype 027 Clostridium difficile requires rapid identification of iso lates in ordertoimplementtimelyinfectioncontrol strategies. Highresolution melt(HRM) analysisof PCRprod ucts can identify strain variation amongst genera of bacteria. The intergenic (16S–23S rDNA) spacer region contains sequenceregionsconserved withingeneraandothersequenceregionvariablesbetweenspecieswithin genera. Wewished toinvestigate whether HRM analysis of PCR ribotyping products could identify ribotype 027 C. difficile. Ribotyping was performed on 93 clinical isolates and five control strains and band patterns were ana lysedusingGelComparII(AppliedMaths,USA).Real-timePCRusingribotypingprimerswasperformedandnor malised melt curves were generated. The HRM data was then imported into ScreenClust software (QIAGEN) to generate principal component analysis graphs depicting clustered relationships of strains. Ribotyping produced clear PCR bands for 88/98 isolates tested. Dendrograms generated by GelCompar showed a diversity of ribotype patterns amongst these 88 isolates with 18 groups identified with 70% homology. One clinical isolate showed 100%homologywiththecontrol027strains. ScreenClustanalysisofthe same88HRMresultsshowedclustering of isolates, with 027 strains identifiable as a unique cluster. HRM analysis correctly identified the control 027 stains and the clinical isolate shown to be 027. HRM combined with ScreenClust analysis of real-time PCR prod ucts of the 16S–23S rDNA spacer region successfully identified ribotype 027 strains. For infection control pur poses this was achieved within 2–3 h of colony isolation.