| PW398289 | Methionine salvage pathway | Reaction compounds not found | | The methionine salvage pathway in bacteria is a vital biochemical route that recycles methionine from methylthioadenosine (MTA), a byproduct generated during polyamine biosynthesis. This pathway is crucial for conserving sulfur-containing compounds and maintaining cellular methionine pools, especially under sulfur-limiting conditions. The process begins with the conversion of MTA into 5-methylthioribose-1-phosphate through a series of enzymatic reactions involving phosphorylation and isomerization. Subsequent steps involve the formation of intermediates like 5-methylthioribulose-1-phosphate, which are enzymatically transformed into 2-keto-4-methylthiobutyrate (KMTB). KMTB is then transaminated to regenerate methionine, often with the involvement of glutamate or other amino donors. The overall pathway efficiently salvages methionine without requiring de novo synthesis from sulfur sources, saving energy and resources. This pathway plays a key role in bacterial survival, as methionine is not only an essential amino acid for protein synthesis but also a precursor for S-adenosylmethionine (SAM), a universal methyl donor in methylation reactions. By recycling methionine, bacteria optimize sulfur metabolism and adapt to nutrient-limited environments, enhancing their competitiveness and growth. |
