6MD3

Structure of T. brucei RRP44 PIN domain

Summary for 6MD3

• Entry DOI: 10.2210/pdb6md3/pdb
• Descriptor: Rrp44p homologue, MANGANESE (II) ION, ZINC ION, ... (5 entities in total)
• Functional Keywords: rrna processing, ribonuclease, rrp44, pin domain, hydrolase-rna complex, hydrolase/rna
• Biological source: Trypanosoma brucei
• Total number of polymer chains: 6
• Total formula weight: 135828.65

Authors

Guimaraes, B.G.,Cesaro, G. (deposition date: 2018-09-03, release date: 2019-01-30, Last modification date: 2024-03-13)

Primary citation

Cesaro, G.,Carneiro, F.R.G.,Avila, A.R.,Zanchin, N.I.T.,Guimaraes, B.G.
Trypanosoma brucei RRP44 is involved in an early stage of large ribosomal subunit RNA maturation.
RNA Biol, 16:133-143, 2019

PubMed Abstract: Ribosomal RNA precursors undergo a series of structural and chemical modifications to generate matured RNA molecules that will comprise ribosomes. This maturation process involves a large set of accessory proteins as well as ribonucleases, responsible for removal of the external and internal transcribed spacers from the pre-rRNA. Early-diverging eukaryotes belonging to the Kinetoplastida class display several unique characteristics, in particular in terms of RNA synthesis and maturation. These peculiarities include the rRNA biogenesis and the extensive fragmentation of the large ribosomal subunit (LSU) rRNA. The role of specific endo- and exonucleases in the maturation of the unusual rRNA precursor of trypanosomatids remains largely unknown. One of the nucleases involved in rRNA processing is Rrp44, an exosome associated ribonuclease in yeast, which is involved in several metabolic RNA pathways. Here, we investigated the function of Trypanosoma brucei RRP44 orthologue (TbRRP44) in rRNA processing. Our results revealed that TbRRP44 depletion causes unusual polysome profile and accumulation of the complete LSU rRNA precursor, in addition to 5.8S maturation impairment. We also determined the crystal structure of TbRRP44 endonucleolytic domain. Structural comparison with Saccharomyces cerevisiae Rrp44 revealed differences in the catalytic site and substitutions of surface residues, which could provide molecular bases for the lack of interaction of RRP44 with the exosome complex in T. brucei.

PubMed: 30593255
DOI: 10.1080/15476286.2018.1564463

Experimental method

X-RAY DIFFRACTION (2.29 Å)