“Aminoacyl tRNA synthetases, class I”的意思、由来-开放百科全书

The aminoacyl-tRNA synthetases ({{EC number|6.1.1.}}) catalyse the attachment of an amino acid to its cognate transfer RNA molecule in a highly specific two-step reaction. These proteins differ widely in size and oligomeric state, and have limited sequence homology.^[1] The 20 aminoacyl-tRNA synthetases are divided into two classes, I and II. Class I aminoacyl-tRNA synthetases contain a characteristic Rossman fold catalytic domain and are mostly monomeric.^[2] Class II aminoacyl-tRNA synthetases share an anti-parallel beta-sheet fold flanked by alpha-helices,^[3] and are mostly dimeric or multimeric, containing at least three conserved regions.^[4]^[5]^[6] However, tRNA binding involves an alpha-helical structure that is conserved between class I and class II synthetases. In reactions catalysed by the class I aminoacyl-tRNA synthetases, the aminoacyl group is coupled to the 2'-hydroxyl of the tRNA, while, in class II reactions, the 3'-hydroxyl site is preferred. The synthetases specific for arginine, cysteine, glutamic acid, glutamine, isoleucine, leucine, methionine, tyrosine, tryptophan and valine belong to class I synthetases; these synthetases are further divided into three subclasses, a, b and c, according to sequence homology. The synthetases specific for alanine, asparagine, aspartic acid, glycine, histidine, lysine, phenylalanine, proline, serine, and threonine belong to class-II synthetases.^[7]

Glutamyl-tRNA synthetase ({{EC number|6.1.1.17}}) is a class Ic synthetase and shows several similarities with glutaminyl-tRNA synthetase concerning structure and catalytic properties. It is an alpha2 dimer. To date one crystal structure of a glutamyl-tRNA synthetase (Thermus thermophilus) has been solved. The molecule has the form of a bent cylinder and consists of four domains. The N-terminal half (domains 1 and 2) contains the 'Rossman fold' typical for class I synthetases and resembles the corresponding part of E. coli GlnRS, whereas the C-terminal half exhibits a GluRS-specific structure.^[8]

Human proteins containing this domain

References

1. ^{{cite journal |vauthors=Delarue M, Moras D, Poch O, Eriani G, Gangloff J |title=Partition of tRNA synthetases into two classes based on mutually exclusive sets of sequence motifs |journal=Nature |volume=347 |issue=6289 |pages=203–206 |year=1990 |pmid=2203971 |doi=10.1038/347203a0}}
2. ^{{cite journal |vauthors=Moras D, Konno M, Shimada A, Nureki O, Tateno M, Yokoyama S, Sugiura I, Ugaji-Yoshikawa Y, Kuwabara S, Lorber B, Giege R |title=The 2.0 A crystal structure of Thermus thermophilus methionyl-tRNA synthetase reveals two RNA-binding modules |journal=Structure |volume=8 |issue=2 |pages=197–208 |year=2000 |pmid=10673435 |doi=10.1016/S0969-2126(00)00095-2}}
3. ^{{cite journal |vauthors=Perona JJ, Steitz TA, Rould MA |title=Structural basis for transfer RNA aminoacylation by Escherichia coli glutaminyl-tRNA synthetase |journal=Biochemistry |volume=32 |issue=34 |pages=8758–8771 |year=1993 |pmid=8364025 |doi=10.1021/bi00085a006}}
4. ^{{cite journal |vauthors=Delarue M, Moras D |title=The aminoacyl-tRNA synthetase family: modules at work |journal=BioEssays |volume=15 |issue=10 |pages=675–687 |year=1993 |pmid=8274143 |doi=10.1002/bies.950151007}}
5. ^{{cite journal |author =Schimmel P |title=Classes of aminoacyl-tRNA synthetases and the establishment of the genetic code |journal=Trends Biochem. Sci. |volume=16 |issue=1 |pages=1–3 |year=1991 |pmid=2053131 |doi=10.1016/0968-0004(91)90002-D}}
6. ^{{cite journal |vauthors=Cusack S, Leberman R, Hartlein M |title=Sequence, structural and evolutionary relationships between class 2 aminoacyl-tRNA synthetases |journal=Nucleic Acids Res. |volume=19 |issue=13 |pages=3489–3498 |year=1991 |pmid=1852601 |doi=10.1093/nar/19.13.3489 |pmc=328370}}
7. ^{{cite journal |author =Bairoch A |title=List of aminoacyl-tRNA synthetases |journal= |volume= |issue= |pages=– |year=2004}}
8. ^{{cite journal |vauthors=Soll D, Freist W, Gauss DH, Lapointe J |title=Glutamyl-tRNA sythetase |journal=Biol. Chem. |volume=378 |issue=11 |pages=1313–1329 |year=1997 |pmid=9426192 | doi = 10.1515/bchm.1997.378.11.1299}}