Download MendeleyCrystal structure of the Entamoeba histolytica RNA lariat debranching enzyme EhDbr1 reveals a catalytic Zn2+/Mn2+heterobinucleation.
Ransey, E., Paredes, E., Dey, S.K., Das, S.R., Heroux, A., Macbeth, M.R.(2017) FEBS Lett 591: 2003-2010
- PubMed: 28504306
- DOI: https://doi.org/10.1002/1873-3468.12677
- Primary Citation of Related Structures:
5UKI - PubMed Abstract:
The RNA lariat debranching enzyme, Dbr1, is a metallophosphoesterase that cleaves 2'-5' phosphodiester bonds within intronic lariats. Previous reports have indicated that Dbr1 enzymatic activity is supported by diverse metal ions including Ni 2+ , Mn 2+ , Mg 2+ , Fe 2+ , and Zn 2+ . While in initial structures of the Entamoeba histolytica Dbr1 only one of the two catalytic metal-binding sites were observed to be occupied (with a Mn 2+ ion), recent structures determined a Zn 2+ /Fe 2+ heterobinucleation. We solved a high-resolution X-ray crystal structure (1.8 Å) of the E. histolytica Dbr1 and determined a Zn 2+ /Mn 2+ occupancy. ICP-AES corroborate this finding, and in vitro debranching assays with fluorescently labeled branched substrates confirm activity.
Organizational Affiliation:
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA.
