1R6L

Crystal Structure Of The tRNA Processing Enzyme Rnase pH From Pseudomonas Aeruginosa

Summary for 1R6L

• Entry DOI: 10.2210/pdb1r6l/pdb
• Related: 1R6M
• Descriptor: Ribonuclease PH, SULFATE ION, 2-[N-CYCLOHEXYLAMINO]ETHANE SULFONIC ACID, ... (4 entities in total)
• Functional Keywords: beta-alpha-beta-alpha fold, hexamer, phosphate bound, transferase
• Biological source: Pseudomonas aeruginosa
• Total number of polymer chains: 1
• Total formula weight: 26748.25

Authors

Choi, J.M.,Park, E.Y.,Kim, J.H.,Chang, S.K.,Cho, Y. (deposition date: 2003-10-15, release date: 2004-02-17, Last modification date: 2024-10-16)

Primary citation

Choi, J.M.,Park, E.Y.,Kim, J.H.,Chang, S.K.,Cho, Y.
Probing the functional importance of the hexameric ring structure of RNase PH
J.BIOL.CHEM., 279:755-764, 2004

PubMed Abstract: RNase PH is a phosphate-dependent exoribonuclease that catalyzes the removal of nucleotides at the 3' end of the tRNA precursor, leading to the release of nucleoside diphosphate, and generates the CCA end during the maturation process. The 1.9-A crystal structures of the apo and the phosphate-bound forms of RNase PH from Pseudomonas aeruginosa reveal a monomeric RNase PH with an alpha/beta-fold tightly associated into a hexameric ring structure in the form of a trimer of dimers. A five ion pair network, Glu-63-Arg-74-Asp-116-Arg-77-Asp-118 and an ion-pair Glu-26-Arg-69 that are positioned symmetrically in the trimerization interface play critical roles in the formation of a hexameric ring. Single or double mutations of Arg-69, Arg-74, or Arg-77 in these ion pairs leads to the dissociation of the RNase PH hexamer into dimers without perturbing the overall monomeric structure. The dissociated RNase PH dimer completely lost its binding affinity and catalytic activity against a precursor tRNA. Our structural and mutational analyses of RNase PH demonstrate that the hexameric ring formation is a critical feature for the function of members of the RNase PH family.

PubMed: 14573594
DOI: 10.1074/jbc.M309628200

Experimental method

X-RAY DIFFRACTION (1.9 Å)