query/ tRNA aminoacylation

[gocentral]

this might be a dim question but isn't tRNA aminoacylation a type of tRNA modification?

Val

Reported by: ValWood

Original Ticket: geneontology/ontology-requests/7185

[gocentral]

Maybe not? An analogy might be that we tend to distinguish covalent modifications of a protein associated with its maturation to an active form from ones that it undergoes in the course of that activity (though the distinction certainly isn't perfect). Here, the modified bases make the tRNA competent to carry out its function, reversible covalent attachment to an amino acid.

Peter

Original comment by: deustp01

[gocentral]

Hi Peter,

I did think along these lines, but many protein modifications are reversible ...phopsphorylation is under modification, but not under maturation....

I agree it would seem odd though, I was just trying to figure out what would exclude it from the current def. Actually I see why. I guess the aminoacylation is not considered to alter the "sequence" of the tRNA and this is how tRNA modifications are defined.

Original comment by: ValWood

[gocentral]

Val The base modifications for the most part are an important part of why a tRNA fold the way it does so that it can be used for aminoacylation, but there are other processes that a tRNA can participate in that is not related to aminoacylation. For example, certain tRNAs can be involved as primers in the reverse transcription needed for some retrovirus life cycles (eg:HIV, lysine tRNA) and also possibly transposition (old memory: have not looked at updates). So I would not link tRNA base modification with aminoacylation. I suppose in certain cases where modification of an anticodon is required before it may be a substrate for a certain synthetase might be considered an important aspect, but only for one of the synthetases (eg: the situation where a tRNA that can be used either for isoleucine or methionine depending on the modification of the anticodon. . By hindering C-34 pairing with G of the third codon position, the minor E. coli tRNAIle reads isoleucine codon AUA and not methionine codon AUG although it has a CUA anticodon.

Since this does not happen across the board, we would need to make a very specific process for only a certain tRNAs;

Original comment by: hdrabkin

[gocentral]

sorry; for some reason after reading Peter's response and having too much coffee, I was thinking you were proposing something else. But no, aminaocylation s not considered a tRNA modification.

Original comment by: hdrabkin

[gocentral]

so can we close this?

Original comment by: mah11

[gocentral]

Yes, sorry I was having a brain storm, you can stop panicking Harold ;)

Original comment by: ValWood

[gocentral]

OK, closing :)

Original comment by: mah11

[gocentral]

• status: open --> closed-works-for-me

Original comment by: mah11

[gocentral]

• milestone: --> PomBase

Original comment by: mah11