6nly

From Proteopedia

Fragment of human mitochondrial Alanyl-tRNA Synthetase C-Ala domain

PDB ID 6nly

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Structural highlights

6nly is a 4 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.307Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

SYAM_HUMAN Combined oxidative phosphorylation defect type 8;Hereditary diffuse leukoencephalopathy with axonal spheroids and pigmented glia;Ovarioleukodystrophy. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry.

Function

SYAM_HUMAN Catalyzes the attachment of alanine to tRNA(Ala) in a two-step reaction: alanine is first activated by ATP to form Ala-AMP and then transferred to the acceptor end of tRNA(Ala). Also edits incorrectly charged tRNA(Ala) via its editing domain.[HAMAP-Rule:MF_03133]

Publication Abstract from PubMed

Metazoan complexity and life-style depend on the bioenergetic potential of mitochondria. However, higher aerobic activity and genetic drift impose strong mutation pressure and risk of irreversible fitness decline in mitochondrial (mt)DNA-encoded genes. Bilaterian mitochondria-encoded tRNA genes, key players in mitochondrial activity, have accumulated mutations at significantly higher rates than their cytoplasmic counterparts, resulting in foreshortened and fragile structures. Here we show that fragility of mt tRNAs coincided with the evolution of bilaterian animals. We demonstrate that bilaterians compensated for this reduced structural complexity in mt tRNAs by sequence-independent induced-fit adaption to the cognate mitochondrial aminoacyl-tRNA synthetase (aaRS). Structural readout by nuclear-encoded aaRS partners relaxed the sequence constraints on mt tRNAs and facilitated accommodation of functionally disruptive mutational insults by cis-acting epistatic compensations. Our results thus suggest that mutational freedom in mt tRNA genes is an adaptation to increased mutation pressure that was associated with the evolution of animal complexity.

Relaxed sequence constraints favor mutational freedom in idiosyncratic metazoan mitochondrial tRNAs.,Kuhle B, Chihade J, Schimmel P Nat Commun. 2020 Feb 20;11(1):969. doi: 10.1038/s41467-020-14725-y. PMID:32080176^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Kuhle B, Chihade J, Schimmel P. Relaxed sequence constraints favor mutational freedom in idiosyncratic metazoan mitochondrial tRNAs. Nat Commun. 2020 Feb 20;11(1):969. doi: 10.1038/s41467-020-14725-y. PMID:32080176 doi:http://dx.doi.org/10.1038/s41467-020-14725-y