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]
Publication Abstract from PubMed
mRNA 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[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Wiseman JS, Nichols JS. Purification and properties of diaminopimelic acid epimerase from Escherichia coli. J Biol Chem. 1984 Jul 25;259(14):8907-14. PMID:6378903
- ↑ Richaud C, Higgins W, Mengin-Lecreulx D, Stragier P. Molecular cloning, characterization, and chromosomal localization of dapF, the Escherichia coli gene for diaminopimelate epimerase. J Bacteriol. 1987 Apr;169(4):1454-9. PMID:3031013
- ↑ Lam LK, Arnold LD, Kalantar TH, Kelland JG, Lane-Bell PM, Palcic MM, Pickard MA, Vederas JC. Analogs of diaminopimelic acid as inhibitors of meso-diaminopimelate dehydrogenase and LL-diaminopimelate epimerase. J Biol Chem. 1988 Aug 25;263(24):11814-9. PMID:3042781
- ↑ Wang Q, Zhang D, Guan Z, Li D, Pei K, Liu J, Zou T, Yin P. DapF stabilizes the substrate-favoring conformation of RppH to stimulate its RNA-pyrophosphohydrolase activity in Escherichia coli. Nucleic Acids Res. 2018 Jun 21. pii: 5042035. doi: 10.1093/nar/gky528. PMID:29931175 doi:http://dx.doi.org/10.1093/nar/gky528