Substrate and Reaction Specificity of Mycobacterium tuberculosis Cytochrome P450 CYP121

Abstract

Background:Little is known about the substrate specificity of the essential P450 CYP121 from Mycobacterium tuberculosis. Results: CYP121 substrate analogues either display impaired binding to CYP121 or are poorly transformed by CYP121. Conclusion: CYP121 is a highly specific P450. Significance: This work contributes to the understanding of the function and the catalytic mechanism of CYP121 and provides novel data for the design of inhibitors.

Comparison of Antifungal Azole Interactions with Adult Cytochrome P450 3A4 versus Neonatal Cytochrome P450 3A7

“…Although direct azole coordination to iron is observed, there is also a second arrangement in which fluconazole forms a hydrogen bond to a water molecule that is in turn coordinated to the heme iron. This water-bridged binding mode has only been observed in a few other bacterial P450 enzyme structures (Poulos and Howard, 1987;Ouellet et al, 2011;Fonvielle et al, 2013), but EPR data suggests this binding mode may be more common in solution (Lockart et al, 2018). Thus, at least two different azole binding modes are documented, though both are inhibitory (Seward et al, 2006).…”

Unrivalled diversity: the many roles and reactions of bacterial cytochromes P450 in secondary metabolism

“…287 Given the essential nature of CYP121 to the survival of M. tuberculosis, 288 this P450 has been extensively characterised by a number of groups, which have afforded structural, biochemical and mechanistic insights into the function of this P450. [289][290][291] Mechanistically, the formation of the C-C bond (similar to aviolin) has been postulated to occur either by via proton coupled electron transfer or electron tunnelling between the two aromatic rings, 177,292 which is a needed to avoid having to completely re-orient the substrate within the active site during catalysis, which was an early mechanistic postulate in this case. 287 One of the more impressive series of transformations reported to occur during bacterial DKP synthesis is found in the biosynthesis of bicyclomycin.…”

A continuous tyrosyl-tRNA synthetase assay that regenerates the tRNA substrate

“…This is the approach that [47]. In M. tuberculosis, cyclodityrosine is converted to mycocyclosin -a putative siderophore -by the actions of the cytochrome P450 CYP121 [48]. Deletion of Rv2276 -the gene encoding CYP121 -is lethal, suggesting that CYP121 may represent a novel antibiotic target in M. tuberculosis [48].…”

“…In M. tuberculosis, cyclodityrosine is converted to mycocyclosin -a putative siderophore -by the actions of the cytochrome P450 CYP121 [48]. Deletion of Rv2276 -the gene encoding CYP121 -is lethal, suggesting that CYP121 may represent a novel antibiotic target in M. tuberculosis [48]. While the lethality of the Rv2276 deletion may be due to either the essential nature of mycocyclosin or the accumulation of cyclodityrosine, the observation that cyclodityrosine synthase can be expressed in E. coli suggests that the accumulation of cyclodityrosine is not toxic to bacterial cells.…”