Structural highlights
Function
HPCD_METS5 Plays a role in autotrophic carbon fixation via the 3-hydroxypropionate/4-hydroxybutyrate cycle. Catalyzes the reversible dehydration of 3-hydroxypropionyl-CoA to form acryloyl-CoA, and the reversible dehydration of (S)-3-hydroxybutyryl-CoA to form crotonyl-CoA. Inactive towards (R)-3-hydroxybutyryl-CoA.[1]
Publication Abstract from PubMed
Metallosphaera sedula is a thermoacidophilic autotrophic archaeon known to utilize the 3-hydroxypropionate/4-hydroxybutyrate cycle (3-HP/4-HB cycle) as carbon fixation pathway. 3-Hydroxypropionyl-CoA dehydratase (3HPCD) is an enzyme involved in the 3-HP/4-HB cycle by converting 3-hydroxypropionyl-CoA to acryloyl-CoA. To elucidate the molecular mechanism of 3HPCD from M. sedula (Ms3HPCD), we determined its crystal structure in complex with Coenzyme A (CoA). Ms3HPCD showed an overall structure and the CoA-binding mode similar to other enoyl-CoA hydratase (ECH) family enzymes. However, compared with the other ECHs, Ms3HPCD has a tightly formed alpha3 helix near the active site, and bulky aromatic residues are located at the enoyl-group binding site, resulting in the enzyme having an optimal substrate binding site for accepting short-chain 3-hydroxyacyl-CoA as a substrate. Moreover, based on the phylogenetic tree analysis, we propose that the 3HPCD homologues from the phylum Crenarchaeota have an enoyl-group binding pocket similar to that of bacterial short-chain ECHs.
Structural Insight into Substrate Specificity of 3-Hydroxypropionyl-Coenzyme A Dehydratase from Metallosphaera sedula.,Lee D, Kim KJ Sci Rep. 2018 Jul 16;8(1):10692. doi: 10.1038/s41598-018-29070-w. PMID:30013155[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Teufel R, Kung JW, Kockelkorn D, Alber BE, Fuchs G. 3-hydroxypropionyl-coenzyme A dehydratase and acryloyl-coenzyme A reductase, enzymes of the autotrophic 3-hydroxypropionate/4-hydroxybutyrate cycle in the Sulfolobales. J Bacteriol. 2009 Jul;191(14):4572-81. doi: 10.1128/JB.00068-09. Epub 2009 May 8. PMID:19429610 doi:http://dx.doi.org/10.1128/JB.00068-09
- ↑ Lee D, Kim KJ. Structural Insight into Substrate Specificity of 3-Hydroxypropionyl-Coenzyme A Dehydratase from Metallosphaera sedula. Sci Rep. 2018 Jul 16;8(1):10692. doi: 10.1038/s41598-018-29070-w. PMID:30013155 doi:http://dx.doi.org/10.1038/s41598-018-29070-w