Gene Ontology annotation through association of InterPro records with GO terms
TreeGrafter-generated GO annotations
Malonyl-coenzyme A reductase in the modified 3-hydroxypropionate cycle for autotrophic carbon fixation in archaeal Metallosphaera and Sulfolobus spp.
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Malonyl-CoA reductase is an ASD paralog. The full text (read on PMC, not cached) assigns the separate S. tokodaii ORF NP_377174 (ST1242), which clusters with aspartokinase and threonine synthase, as the true asd, without expressing or assaying it. Msed_1700 is not tested.
"Malonyl-CoA reductase has 38% amino acid sequence identity to aspartate-semialdehyde dehydrogenase, suggesting a common ancestor for both proteins."
The genome sequence of the metal-mobilizing, extremely thermoacidophilic archaeon Metallosphaera sedula provides insights into bioleaching-associated metabolism.
Malonic semialdehyde reductase, succinic semialdehyde reductase, and succinyl-coenzyme A reductase from Metallosphaera sedula: enzymes of the autotrophic 3-hydroxypropionate/4-hydroxybutyrate cycle in Sulfolobales.
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Peptide mass fingerprinting of the native succinyl-CoA/malonyl-CoA reductase from autotrophic M. sedula matched only Msed_0709, not Msed_1700.
"The only hit was with the gene gi|146303492 (100% identity, 54% coverage) annotated as an aspartate-semialdehyde dehydrogenase gene coding for a 39.2-kDa protein (Msed_0709; 357 amino acids)."
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The ASD gene was duplicated in the Sulfolobales ancestor, and the two copies diverged in function.
"A phylogenetic tree of the gene ( 1 , 9 ) suggests that there was duplication of the aspartate semialdehyde dehydrogenase gene in the ancestor of the Sulfolobales and that there was independent evolution of the two genes to perform different functions."
Structural basis for a bispecific NADP+ and CoA binding site in an archaeal malonyl-coenzyme A reductase.
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In Sulfolobales the asd gene clusters with threonine synthase and aspartokinase, while mcr has no conserved neighbours.
"The asd gene clusters together with threonine synthase, aspartokinase, and ornithine carbamoyltransferase, among other genes, which is in line with its role in the biosynthesis of amino acids of the aspartate family."
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The archaeal M. jannaschii ASD binds NADP+ and has dual NADPH/NADH specificity with a preference for NADPH.
"This difference rationalizes its dual specificity for NADPH and NADH as electron donor, albeit still with a clear preference for NADPH ( 18 )."
A new branch in the family: structure of aspartate-beta-semialdehyde dehydrogenase from Methanococcus jannaschii.
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The archaeal ASD branch keeps all the catalytic residues and has dual NAD/NADP specificity.
"A new coenzyme-binding conformation and dual NAD/NADP coenzyme specificity further distinguish this archaeal branch from the bacterial ASADHs."
Structural Insights into the Tetrameric State of Aspartate-β-semialdehyde Dehydrogenases from Fungal Species.
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ASDs of the archaeal/fungal branch, including the M. jannaschii enzyme, form GAPDH-like homotetramers. Tetramerization is required for activity in the fungal enzyme.
"Further, our structural analyses and native PAGE results with other fungal ASADHs demonstrated that ASADH tetramerization is universal in the archaeal/fungal branch."
UniProt record A4YHF3 (A4YHF3_METS5)
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The ARBA-derived name and CATALYTIC ACTIVITY call the protein a malonyl-CoA reductase (EC 1.2.1.75). This conflicts with its ASD-type CDD models, its asd genomic context, and the experimental assignment of MCR to Msed_0709.
"RecName: Full=malonyl CoA reductase (malonate semialdehyde-forming)"
Msed_1700 versus MCR paralog and reference ASD comparison
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Msed_1700 is 69% identical to the S. tokodaii asd (ST1242) and about 39-41% identical to the MCRs. It carries ASD-type CDD models. About 17 of the 40 archaeal UniProt entries named EC 1.2.1.75 are ASD-type.
"Msed_1700 is far closer to the S. tokodaii asd gene product (ST1242) than to either MCR."