Methionine oxidation does not reach full penetrance and 85% of the characterized modification sites show oxidation levels of ∼30%.
Finally, MS analysis of HA-eEF1A mimicking the yeast eEF1A sequence around the EPG modification site showed the presence of the EPG-modified peptide, FDE*LLEK (Table 1).
In 31 instances, it was the only modification detected on a given site, whereas the remaining 5 sites showed alternative modification variants, including mono-, di- and tri-methylation (three, four, and four sites, respectively).
A higher fraction of non A-to-G sites show ∼50% modification levels (compared to the A-to-G sites), indicating a higher fraction of missed genomic polymorphisms.
But only one site showed that trend.
However, analysis of the EXO primary structure did not reveal a GPI modification site, and plasmolysis experiments showed that the EXO protein was not associated with the plasma membrane.
Note: snoRNA of E. histolytica and its homolog in yeast (Y), Human (H), P. falciparum (P) and T. brucei (T) is shown with their conserved modification sites.
In this theoretical study, we show that a simple substrate with two modification sites acted upon by two opposing enzymes (e.g., a kinase and a phosphatase) can show oscillations in its modification state.
4, 15 Structural analysis has recently shown that protein protein interfaces are enriched for modification sites.
Table 1 shows the proportion of overlap between experimentally determined modification sites and our computational predictions for Arabidopsis, yeast and human.
