YcaO is a protein found in bacteria which is involved in the synthesis of thiazole/oxazole modified
microcin antibiotics, such as
bottromycin. YcaO performs
ATP dependent cyclodehydration to form the
oxazole and
thiazole moieties of the microcin.[2][3][4]
The YcaO name origin is from a gene naming rubric that was established from the bacterium
Escherichia coli. If a gene has an unknown function, it was given a four-letter name starting with the letter Y and the next three letters are given based on the genomic location. [5]
Methyl coenzyme M reductase (MCR) or
Coenzyme-B sulfoethylthiotransferase is a protein known in thioamidation (a posttranslational modification). A Ycao enzyme dependent on ATP is needed for MCR thioamidation as well as a sulfide source. YcaO enzymes are needed to catalyze the ATP-dependent backbone cyclodehydration of polar amino acids such as
Cysteine,
Serine, and
Threonine to the correct thiazoline and (methyl) oxazoline
Heterocycle.[6] The side chains of these amino acids can act as
Nucleophiles. The
Thiol group in cysteine and the hydroxyl group of serine and threonine are strong nucleophiles.