3CW5

E. coli Initiator tRNA

Summary for 3CW5

• Entry DOI: 10.2210/pdb3cw5/pdb
• Related: 3CW6
• Descriptor: Initiator tRNA (1 entity in total)
• Functional Keywords: trna, initiator, rna
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 24832.92

Authors

Barraud, P.,Schmitt, E.,Mechulam, Y.,Dardel, F.,Tisne, C. (deposition date: 2008-04-21, release date: 2008-09-02, Last modification date: 2023-08-30)

Primary citation

Barraud, P.,Schmitt, E.,Mechulam, Y.,Dardel, F.,Tisne, C.
A unique conformation of the anticodon stem-loop is associated with the capacity of tRNAfMet to initiate protein synthesis.
Nucleic Acids Res., 36:4894-4901, 2008

PubMed Abstract: In all organisms, translational initiation takes place on the small ribosomal subunit and two classes of methionine tRNA are present. The initiator is used exclusively for initiation of protein synthesis while the elongator is used for inserting methionine internally in the nascent polypeptide chain. The crystal structure of Escherichia coli initiator tRNA(f)(Met) has been solved at 3.1 A resolution. The anticodon region is well-defined and reveals a unique structure, which has not been described in any other tRNA. It encompasses a Cm32*A38 base pair with a peculiar geometry extending the anticodon helix, a base triple between A37 and the G29-C41 pair in the major groove of the anticodon stem and a modified stacking organization of the anticodon loop. This conformation is associated with the three GC basepairs in the anticodon stem, characteristic of initiator tRNAs and suggests a mechanism by which the translation initiation machinery could discriminate the initiator tRNA from all other tRNAs.

PubMed: 18653533
DOI: 10.1093/nar/gkn462

Experimental method

X-RAY DIFFRACTION (3.1 Å)