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In enzymology, glutamate racemase (MurI with a capital ''i'') () is an enzyme that catalyzes the chemical reaction :L-glutamate D-glutamate Hence, this enzyme RacE has one substrate, L-glutamate, and one product, D-glutamate. This enzyme belongs to the family of isomerases, specifically those racemases and epimerases acting on amino acids and derivatives, including proline racemase, aspartate racemase, and diaminopimelate epimerase.〔 This enzyme participates in glutamate metabolism that is essential for cell wall biosynthesis in bacteria. Glutamate racemase performs the additional function of gyrase inhibition, preventing gyrase from binding to DNA. Glutamate racemase (MurI) serves two distinct metabolic functions: primarily, it is a critical enzyme in cell wall biosynthesis,〔 but also plays a role in gyrase inhibition.〔 The ability of glutamate racemase and other proteins to serve two distinct functions is known as "moonlighting". ==Moonlighting background== (詳細はmoonlighting proteins, it was generally believed by scientists that an enzyme only had one function which lead to the concept of "one gene, one enzyme". However, this concept no longer applies in science after the discovery that some proteins consist of both major and minor functions. This led to numerous studies attempting to relate the two functions to each other. The minor functions of these unique enzymes are called moonlighting functions, in which a protein can have a secondary functions not dependent upon the main function. These two functions of the moonlighting protein are found in a single polypeptide chain. Proteins that are multifunctional are not included due to gene fusion, families of homologous proteins, splice variants or promiscuous enzyme activities. The enzyme glutamate racemase (MurI) is an example of a moonlighting protein, functioning both in bacterial cell wall biosynthesis as well as in gyrase inhibition. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Glutamate racemase」の詳細全文を読む スポンサード リンク
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