1j2b
Crystal Structure Of Archaeosine tRNA-Guanine Transglycosylase Complexed With lambda-form tRNA(Val)Crystal Structure Of Archaeosine tRNA-Guanine Transglycosylase Complexed With lambda-form tRNA(Val)
Structural highlights
FunctionATGT_PYRHO Exchanges the guanine residue with 7-cyano-7-deazaguanine (preQ0) at position 15 in the dihydrouridine loop (D-loop) of archaeal tRNAs.[HAMAP-Rule:MF_01634] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedTransfer RNA (tRNA) canonically has the clover-leaf secondary structure with the acceptor, D, anticodon, and T arms, which are folded into the L-shaped tertiary structure. To strengthen the L form, posttranscriptional modifications occur on nucleotides buried within the core, but the modification enzymes are paradoxically inaccessible to them in the L form. In this study, we determined the crystal structure of tRNA bound with archaeosine tRNA-guanine transglycosylase, which modifies G15 of the D arm in the core. The bound tRNA assumes an alternative conformation ("lambda form") drastically different from the L form. All of the D-arm secondary base pairs and the canonical tertiary interactions are disrupted. Furthermore, a helical structure is reorganized, while the rest of the D arm is single stranded and protruded. Consequently, the enzyme precisely locates the exposed G15 in the active site, by counting the nucleotide number from G1 to G15 in the lambda form. Alternative tertiary structure of tRNA for recognition by a posttranscriptional modification enzyme.,Ishitani R, Nureki O, Nameki N, Okada N, Nishimura S, Yokoyama S Cell. 2003 May 2;113(3):383-94. PMID:12732145[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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