7vwy
Crystal structure of (+)-pulegone reductase from Mentha piperita
Structural highlights
FunctionRPOA_ECOLI DNA-dependent RNA polymerase catalyzes the transcription of DNA into RNA using the four ribonucleoside triphosphates as substrates. This subunit plays an important role in subunit assembly since its dimerization is the first step in the sequential assembly of subunits to form the holoenzyme.[HAMAP-Rule:MF_00059] Publication Abstract from PubMedRob, which serves as a paradigm of the large AraC/XylS family transcription activators, regulates diverse subsets of genes involved in multidrug resistance and stress response. However, the underlying mechanism of how it engages bacterial RNA polymerase and promoter DNA to finely respond to environmental stimuli is still elusive. Here, we present two cryo-EM structures of Rob-dependent transcription activation complex (Rob-TAC) comprising of Escherichia coli RNA polymerase (RNAP), Rob-regulated promoter and Rob in alternative conformations. The structures show that a single Rob engages RNAP by interacting with RNAP alphaCTD and sigma70R4, revealing their generally important regulatory roles. Notably, by occluding sigma70R4 from binding to -35 element, Rob specifically binds to the conserved Rob binding box through its consensus HTH motifs, and retains DNA bending by aid of the accessory acidic loop. More strikingly, our ligand docking and biochemical analysis demonstrate that the large Rob C-terminal domain (Rob CTD) shares great structural similarity with the global Gyrl-like domains in effector binding and allosteric regulation, and coordinately promotes formation of competent Rob-TAC. Altogether, our structural and biochemical data highlight the detailed molecular mechanism of Rob-dependent transcription activation, and provide favorable evidences for understanding the physiological roles of the other AraC/XylS-family transcription factors. Structural basis of transcription activation by Rob, a pleiotropic AraC/XylS family regulator.,Shi J, Wang F, Li F, Wang L, Xiong Y, Wen A, Jin Y, Jin S, Gao F, Feng Z, Li J, Zhang Y, Shang Z, Wang S, Feng Y, Lin W Nucleic Acids Res. 2022 Jun 10;50(10):5974-5987. doi: 10.1093/nar/gkac433. PMID:35641097[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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