Sandbox Reserved 325: Difference between revisions
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==Introduction== | ==Introduction== | ||
The gene Rv1885c from ''Mycobacteriam tuberculosis'' encodes for a non-functional chorismate mutase (*MtCM)<ref name="pizza" />. This non-functional mutase has a 33-amino-acid cleavable sequence. It is a vital enzyme in the shikimate pathway, which allows for the synthesis of tryptophan, tyrosinem and phenylalanine <ref name="pizza" />. Chorismate mutase only occurs in bacteria, higher plants, and fungi, due to the fact that the shikimate pathway is only found in these organisms <ref name="strat" />. In ''Escherichia coli'', chorismate mutase has a periplasmic destination<ref name="pizza" />. In ''M. tuberculosis'' there is in abscence of a periplasmic compartment for chorismate mutase, so it secretes into the culture filtrate of ''M. tuberculosis''<ref name="pizza" /> | The gene Rv1885c from ''Mycobacteriam tuberculosis'' encodes for a non-functional chorismate mutase (*MtCM)<ref name="pizza" />. This non-functional mutase has a 33-amino-acid cleavable sequence. It is a vital enzyme in the shikimate pathway, which allows for the synthesis of tryptophan, tyrosinem and phenylalanine <ref name="pizza" />. Chorismate mutase only occurs in bacteria, higher plants, and fungi, due to the fact that the shikimate pathway is only found in these organisms <ref name="strat" />. In ''Escherichia coli'', chorismate mutase has a periplasmic destination<ref name="pizza" />. In ''M. tuberculosis'' there is in abscence of a periplasmic compartment for chorismate mutase, so it secretes into the culture filtrate of ''M. tuberculosis''<ref name="pizza" /> | ||
Rv1185c is synthesized along with an amino acid terminal sequence, which is cleaved off from the mature protein when expressed with e coli | |||
Chorismate mutase is an essential enzyme in the shikimate pathway <ref name="pizza"> PMID:17146044 </ref>. This pathway allows for the biosynthesis of aromatic amino acids tryptophan, tyrosine, and phenylalanine <ref name="pizza" />. The production of tyrosine and phenylalanine is achieved by what is called a Claisen arrangement. first converting chorismate to prephenate. Prephenate then reacts with prephenate dehydratase and prephenate dehydrogenase which forms phenylpyruvate and hydroxyphenylpyruvate. After this occursm aminotransferase converts hydroxy-phenylpyruvate and phenylpyruvate to phenylalanine and tyrosine. Chorismate mutase provides a 2x10<sup>6</sup> fold increase in the rate of reaction, in comparison to the uncatalyzed reaction <ref > P.D. Lyne, A.J. Mulholland, W.G. Richards. Insights into chorismate mutase catalysis from a combined qm/mm simulation of the enzyme reaction. Journal of the American Chemistry Society. 1995 117(45):11345-11350</ref>. It is the only example of an enzyme catalyzing a percyclic reaction <ref name="strat"> PMID:10960481 </ref> | Chorismate mutase is an essential enzyme in the shikimate pathway <ref name="pizza"> PMID:17146044 </ref>. This pathway allows for the biosynthesis of aromatic amino acids tryptophan, tyrosine, and phenylalanine <ref name="pizza" />. The production of tyrosine and phenylalanine is achieved by what is called a Claisen arrangement. first converting chorismate to prephenate. Prephenate then reacts with prephenate dehydratase and prephenate dehydrogenase which forms phenylpyruvate and hydroxyphenylpyruvate. After this occursm aminotransferase converts hydroxy-phenylpyruvate and phenylpyruvate to phenylalanine and tyrosine. Chorismate mutase provides a 2x10<sup>6</sup> fold increase in the rate of reaction, in comparison to the uncatalyzed reaction <ref > P.D. Lyne, A.J. Mulholland, W.G. Richards. Insights into chorismate mutase catalysis from a combined qm/mm simulation of the enzyme reaction. Journal of the American Chemistry Society. 1995 117(45):11345-11350</ref>. It is the only example of an enzyme catalyzing a percyclic reaction <ref name="strat"> PMID:10960481 </ref> | ||
==Structure== | ==Structure== | ||
<Structure load='2f6l' size='300' frame='true' align='left' caption='Insert caption here' scene='Sandbox_Reserved_325/Chainbows/1' /> | <Structure load='2f6l' size='300' frame='true' align='left' caption='Insert caption here' scene='Sandbox_Reserved_325/Chainbows/1' /> | ||
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has an all alpha helical structure | has an all alpha helical structure | ||
active site forms in single chain without help from second half of dimer | active site forms in single chain without help from second half of dimer | ||
active site is critical for catalysis. it is made up of Arg 49, Lys 60, Arg 72, Thr 105, Glu 109, and Arg 134 | |||
not regulated by aromatic amino acids, which is supported by the fact that there are no allosteric regulatory sites. | |||
alpha helicalstruc similar to e coli CM and S. cerevisae CM | |||
here is a <scene name='Sandbox_Reserved_325/Disulfide/1'>disulfide bridge</scene> | here is a <scene name='Sandbox_Reserved_325/Disulfide/1'>disulfide bridge</scene> | ||
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==Chorismate Mutase and Tuberculosis== | ==Chorismate Mutase and Tuberculosis== | ||
may be involved in pathogenesis. | |||
one can take advantage of non-occurance of CMs in humans to try to develop antimicrobial drugs for human pathogens such as tb | |||
==References== | ==References== | ||
<references/> | <references/> | ||
