Lysine and arginine biosyntheses mediated by a common carrier protein in Sulfolobus
One pathway for lysine biosynthesis uses a carrier protein, LysW, to protect the substrate. LysW is now shown to mediate entry of a second substrate into the same metabolic pathway, with structural and biochemical evidence identifying an amino acid motif that determines substrate specificity. LysW h...
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Published in | Nature chemical biology Vol. 9; no. 4; pp. 277 - 283 |
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Main Authors | , , , , , , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
New York
Nature Publishing Group US
01.04.2013
Nature Publishing Group |
Subjects | |
Online Access | Get full text |
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Summary: | One pathway for lysine biosynthesis uses a carrier protein, LysW, to protect the substrate. LysW is now shown to mediate entry of a second substrate into the same metabolic pathway, with structural and biochemical evidence identifying an amino acid motif that determines substrate specificity.
LysW has been identified as a carrier protein in the lysine biosynthetic pathway that is active through the conversion of α-aminoadipate (AAA) to lysine. In this study, we found that the hyperthermophilic archaeon,
Sulfolobus acidocaldarius
, not only biosynthesizes lysine through LysW-mediated protection of AAA but also uses LysW to protect the amino group of glutamate in arginine biosynthesis. In this archaeon, after LysW modification, AAA and glutamate are converted to lysine and ornithine, respectively, by a single set of enzymes with dual functions. The crystal structure of ArgX, the enzyme responsible for modification and protection of the amino moiety of glutamate with LysW, was determined in complex with LysW. Structural comparison and enzymatic characterization using
Sulfolobus
LysX,
Sulfolobus
ArgX and
Thermus
LysX identify the amino acid motif responsible for substrate discrimination between AAA and glutamate. Phylogenetic analysis reveals that gene duplication events at different stages of evolution led to ArgX and LysX. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 1552-4450 1552-4469 |
DOI: | 10.1038/nchembio.1200 |