title: Crystal structure of RNase T, an exoribonuclease involved in tRNA maturation and end turnover.
abstract: The 3' processing of most bacterial precursor tRNAs involves exonucleolytic trimming to yield a mature CCA end. This step is carried out by RNase T, a member of the large DEDD family of exonucleases. We report the crystal structures of RNase T from Escherichia coli and Pseudomonas aeruginosa, which show that this enzyme adopts an opposing dimeric arrangement, with the catalytic DEDD residues from one monomer closely juxtaposed with a large basic patch on the other monomer. This arrangement suggests that RNase T has to be dimeric for substrate specificity, and agrees very well with prior site-directed mutagenesis studies. The dimeric architecture of RNase T is very similar to the arrangement seen in oligoribonuclease, another bacterial DEDD family exoribonuclease. The catalytic residues in these two enzymes are organized very similarly to the catalytic domain of the third DEDD family exoribonuclease in E. coli, RNase D, which is monomeric.
authors: Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, FL 33101, USA.
authors: Yuhong
authors: Y
authors: Zuo
authors: Heping
authors: H
authors: Zheng
authors: Yong
authors: Y
authors: Wang
authors: Maksymilian
authors: M
authors: Chruszcz
authors: Marcin
authors: M
authors: Cymborowski
authors: Tatiana
authors: T
authors: Skarina
authors: Alexei
authors: A
authors: Savchenko
authors: Arun
authors: A
authors: Malhotra
authors: Wladek
authors: W
authors: Minor
mesh_terms: D000595:Amino Acid Sequence; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D005095:Exoribonucleases / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000235:genetics; D012343:RNA, Transfer / Q000737:chemistry* / Q000378:metabolism
chemical_list: D012343:RNA, Transfer; D005095:Exoribonucleases; C042081:exoribonuclease T