Header

UZH-Logo

Maintenance Infos

Crystal structure of Saccharomyces cerevisiae mitochondrial GatFAB reveals a novel subunit assembly in tRNA-dependent amidotransferases


Araiso, Yuhei; Huot, Jonathan L; Sekiguchi, Takuya; Frechin, Mathieu; Fischer, Frédéric; Enkler, Ludovic; Senger, Bruno; Ishitani, Ryuichiro; Becker, Hubert D; Nureki, Osamu (2014). Crystal structure of Saccharomyces cerevisiae mitochondrial GatFAB reveals a novel subunit assembly in tRNA-dependent amidotransferases. Nucleic Acids Research, 42(9):6052-6063.

Abstract

Yeast mitochondrial Gln-mtRNAGln is synthesized by the transamidation of mischarged Glu-mtRNAGln by a non-canonical heterotrimeric tRNA-dependent amidotransferase (AdT). The GatA and GatB subunits of the yeast AdT (GatFAB) are well conserved among bacteria and eukaryota, but the GatF subunit is a fungi-specific ortholog of the GatC subunit found in all other known heterotrimeric AdTs (GatCAB). Here we report the crystal structure of yeast mitochondrial GatFAB at 2.0 Å resolution. The C-terminal region of GatF encircles the GatA-GatB interface in the same manner as GatC, but the N-terminal extension domain (NTD) of GatF forms several additional hydrophobic and hydrophilic interactions with GatA. NTD-deletion mutants displayed growth defects, but retained the ability to respire. Truncation of the NTD in purified mutants reduced glutaminase and transamidase activities when glutamine was used as the ammonia donor, but increased transamidase activity relative to the full-length enzyme when the donor was ammonium chloride. Our structure-based functional analyses suggest the NTD is a trans-acting scaffolding peptide for the GatA glutaminase active site. The positive surface charge and novel fold of the GatF-GatA interface, shown in this first crystal structure of an organellar AdT, stand in contrast with the more conventional, negatively charged bacterial AdTs described previously

Abstract

Yeast mitochondrial Gln-mtRNAGln is synthesized by the transamidation of mischarged Glu-mtRNAGln by a non-canonical heterotrimeric tRNA-dependent amidotransferase (AdT). The GatA and GatB subunits of the yeast AdT (GatFAB) are well conserved among bacteria and eukaryota, but the GatF subunit is a fungi-specific ortholog of the GatC subunit found in all other known heterotrimeric AdTs (GatCAB). Here we report the crystal structure of yeast mitochondrial GatFAB at 2.0 Å resolution. The C-terminal region of GatF encircles the GatA-GatB interface in the same manner as GatC, but the N-terminal extension domain (NTD) of GatF forms several additional hydrophobic and hydrophilic interactions with GatA. NTD-deletion mutants displayed growth defects, but retained the ability to respire. Truncation of the NTD in purified mutants reduced glutaminase and transamidase activities when glutamine was used as the ammonia donor, but increased transamidase activity relative to the full-length enzyme when the donor was ammonium chloride. Our structure-based functional analyses suggest the NTD is a trans-acting scaffolding peptide for the GatA glutaminase active site. The positive surface charge and novel fold of the GatF-GatA interface, shown in this first crystal structure of an organellar AdT, stand in contrast with the more conventional, negatively charged bacterial AdTs described previously

Statistics

Citations

Dimensions.ai Metrics
10 citations in Web of Science®
9 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

16 downloads since deposited on 08 Nov 2018
8 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:National licences > 142-005
Dewey Decimal Classification:570 Life sciences; biology
610 Medicine & health
Scopus Subject Areas:Life Sciences > Genetics
Language:English
Date:14 May 2014
Deposited On:08 Nov 2018 17:37
Last Modified:15 Apr 2020 21:12
Publisher:Oxford University Press
ISSN:0305-1048
OA Status:Gold
Free access at:PubMed ID. An embargo period may apply.
Publisher DOI:https://doi.org/10.1093/nar/gku234
Related URLs:https://www.swissbib.ch/Search/Results?lookfor=nationallicenceoxford101093nargku234 (Library Catalogue)
PubMed ID:24692665

Download

Gold Open Access

Download PDF  'Crystal structure of Saccharomyces cerevisiae mitochondrial GatFAB reveals a novel subunit assembly in tRNA-dependent amidotransferases'.
Preview
Content: Published Version
Language: English
Filetype: PDF (Nationallizenz 142-005)
Size: 3MB
View at publisher
Licence: Creative Commons: Attribution 3.0 Unported (CC BY 3.0)