5ygu
From Proteopedia
Crystal structure of Escherichia coli (strain K12) mRNA Decapping Complex RppH-DapF
Structural highlights
Function[DAPF_ECOLI] Catalyzes the stereoinversion of LL-2,6-diaminoheptanedioate (L,L-DAP) to meso-diaminoheptanedioate (meso-DAP), a precursor of L-lysine and an essential component of the bacterial peptidoglycan. Only accepts DAP isomers with the L configuration.[1] [2] [3] [RPPH_ECOLI] Master regulator of 5'-dependent mRNA decay. Accelerates the degradation of transcripts by removing pyrophosphate from the 5'-end of triphosphorylated RNA, leading to a more labile monophosphorylated state that can stimulate subsequent ribonuclease cleavage. Preferentially hydrolyzes diadenosine penta-phosphate with ATP as one of the reaction products. Also able to hydrolyze diadenosine hexa- and tetra-phosphate. Has no activity on diadenosine tri-phosphate, ADP-ribose, NADH and UDP-glucose. In the meningitis causing strain E.coli K1, has been shown to play a role in HBMEC (human brain microvascular endothelial cells) invasion in vitro.[4] [5] Publication Abstract from PubMedmRNA decay is an important strategy by which bacteria can rapidly adapt to their ever-changing surroundings. The 5'-terminus state of mRNA determines the velocity of decay of many types of RNA. In Escherichia coli, RNA pyrophosphohydrolase (RppH) is responsible for the removal of the 5'-terminal triphosphate from hundreds of mRNAs and triggers its rapid degradation by ribonucleases. A diaminopimelate epimerase, DapF, can directly interact with RppH and stimulate its hydrolysis activity in vivo and in vitro. However, the molecular mechanism remains to be elucidated. Here, we determined the complex structure of DapF-RppH as a heterotetramer in a 2:2 molar ratio. DapF-bound RppH exhibits an RNA-favorable conformation similar to the RNA-bound state, suggesting that association with DapF promotes and stabilizes RppH in a conformation that facilitates substrate RNA binding and thus stimulates the activity of RppH. To our knowledge, this is the first published structure of an RNA-pyrophosphohydrolysis complex in bacteria. Our study provides a framework for further investigation of the potential regulators involved in the RNA-pyrophosphohydrolysis process in prokaryotes. DapF stabilizes the substrate-favoring conformation of RppH to stimulate its RNA-pyrophosphohydrolase activity in Escherichia coli.,Wang Q, Zhang D, Guan Z, Li D, Pei K, Liu J, Zou T, Yin P Nucleic Acids Res. 2018 Jun 21. pii: 5042035. doi: 10.1093/nar/gky528. PMID:29931175[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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