PDBsum entry 3wfo

Transferase

PDB id: 3wfo

Contents

Protein chains

425 a.a.

Ligands

SO4 ×11

PDB id:

3wfo

Name:

Transferase

Title:

tRNA processing enzyme (apo form 1)

Structure:

Poly a polymerase. Chain: a, b, c. Engineered: yes

Source:

Aquifex aeolicus. Organism_taxid: 224324. Strain: vf5. Gene: pcnb2. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

3.40Å R-factor: 0.181 R-free: 0.210

Authors:

S.Yamashita,D.Takeshita,K.Tomita

Key ref:

S.Yamashita et al. (2014). Translocation and rotation of tRNA during template-independent RNA polymerization by tRNA nucleotidyltransferase. Structure, 22, 315-325. PubMed id: 24389024 DOI: 10.1016/j.str.2013.12.002

Date:

23-Jul-13 Release date: 01-Jan-14

Protein chains

O67911  (O67911_AQUAE) -  CC-adding tRNA nucleotidyltransferase from Aquifex aeolicus (strain VF5)

Seq: 512 a.a.

Struc: 425 a.a.

Enzyme reactions

• Enzyme class: E.C.2.7.7.- - ?????

DOI no: 10.1016/j.str.2013.12.002

Structure 22:315-325 (2014)

PubMed id: 24389024

Translocation and rotation of tRNA during template-independent RNA polymerization by tRNA nucleotidyltransferase.

S.Yamashita, D.Takeshita, K.Tomita.

ABSTRACT

The 3'-terminal CCA (CCA-3' at positions 74-76) of tRNA is synthesized by CCA-adding enzyme using CTP and ATP as substrates, without a nucleic acid template. In Aquifex aeolicus, CC-adding and A-adding enzymes collaboratively synthesize the CCA-3'. The mechanism of CCA-3' synthesis by these two enzymes remained obscure. We now present crystal structures representing CC addition onto tRNA by A. aeolicus CC-adding enzyme. After C₇₄ addition in an enclosed active pocket and pyrophosphate release, the tRNA translocates and rotates relative to the enzyme, and C₇₅ addition occurs in the same active pocket as C₇₄ addition. At both the C₇₄-adding and C₇₅-adding stages, CTP is selected by Watson-Crick-like hydrogen bonds between the cytosine of CTP and conserved Asp and Arg residues in the pocket. After C₇₄C₇₅ addition and pyrophosphate release, the tRNA translocates further and drops off the enzyme, and the CC-adding enzyme terminates RNA polymerization.