Description

IPR000506 is a Ketol-acid reductoisomerase, C-terminal.

<p>Ketol-acid reductoisomerase (KARI; ([ec:1.1.1.86])), also known as acetohydroxy acid isomeroreductase (AHIR or AHAIR), catalyzes the conversion of acetohydroxy acids into dihydroxy valerates in the second step of the biosynthetic pathway for the essential branched-chain amino acids valine, leucine, and isoleucine. KARI catalyzes an unusual two-step reaction consisting of an alkyl migration in which the substrate, either 2-acetolactate (AL) or 2-aceto-2-hydroxybutarate (AHB), is converted to 3-hydoxy-3-methyl-2- oxobutyrate or 3-hydoxy-3-methyl-2-pentatonate, followed by a NADPH-dependent reduction to give 2,3-dihydroxy-3-isovalerate or 2,3-dihydroxy-3- methylvalerate respectively [[cite:PUB00001302], [cite:PUB00088660], [cite:PUB00029172], [cite:PUB00034453], [cite:PUB00088661], [cite:PUB00088662]].</p> <p>KARI is present only in bacteria, fungi, and plants, but not in animals. KARIs are divided into two classes on the basis of sequence length and oligomerization state. Class I KARIs are ~340 amino acid residues in length and include all fungal KARIs, whereas class II KARIs are ~490 residues long and include all plant KARIs. Bacterial KARIs can be either class I or class II. KARIs are composed of two types of domains, an N-terminal Rossmann fold domain and one or two C-terminal knotted domains. Two intertwinned knotted domains are required for function, and in the short-chain or class I KARIs, each polypeptide chain has one knotted domain. As a result, dimerization of two monomers forms two complete KARI active sites. In the long-chain or class II KARIs, a duplication of the knotted domain has occurred and, as a result, the protein does not require dimerization to complete its active site [[cite:PUB00001302], [cite:PUB00088660], [cite:PUB00029172], [cite:PUB00034453], [cite:PUB00088661], [cite:PUB00088662]].</p> <p>The α-helical KARI C-terminal knotted domain can be described as a six- helix core in which helices coil like cable threads around each other, thus forming a bundle [[cite:PUB00001302], [cite:PUB00088660], [cite:PUB00029172], [cite:PUB00034453], [cite:PUB00088661]].</p>

This description is obtained from EB-eye REST.

Associated GO terms

GO predictions are based solely on the InterPro-to-GO mappings published by EMBL-EBI, which are in turn based on the mapping of predicted domains to the InterPro dataset. The InterPro-to-GO mapping was last updated on April 27, 2020, while the GO metadata was last updated on April 27, 2020.

Associated Lotus transcripts 5

Co-occuring domains 1

A list of co-occurring predicted domains within the L. japonicus gene space: