Enzymes
| UniProtKB help_outline | 2 proteins |
Reaction participants Show >> << Hide
- Name help_outline N-acetyl-β-neuraminate Identifier CHEBI:58705 (Beilstein: 4822969) help_outline Charge -1 Formula C11H18NO9 InChIKeyhelp_outline SQVRNKJHWKZAKO-PFQGKNLYSA-M SMILEShelp_outline [H][C@]1(O[C@@](O)(C[C@H](O)[C@H]1NC(C)=O)C([O-])=O)[C@H](O)[C@H](O)CO 2D coordinates Mol file for the small molecule Search links Involved in 2 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline aceneuramate Identifier CHEBI:173083 Charge -1 Formula C11H18NO9 InChIKeyhelp_outline KBGAYAKRZNYFFG-BOHATCBPSA-M SMILEShelp_outline CC(=O)N[C@H]([C@@H](O)CC(=O)C([O-])=O)[C@@H](O)[C@H](O)[C@H](O)CO 2D coordinates Mol file for the small molecule Search links Involved in 3 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
| RHEA:67740 | RHEA:67741 | RHEA:67742 | RHEA:67743 | |
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| Reaction direction help_outline | undefined | left-to-right | right-to-left | bidirectional |
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Publications
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The metalloprotein YhcH is an anomerase providing N-acetylneuraminate aldolase with the open form of its substrate.
Kentache T., Thabault L., Deumer G., Haufroid V., Frederick R., Linster C.L., Peracchi A., Veiga-da-Cunha M., Bommer G.T., Van Schaftingen E.
N-acetylneuraminate (Neu5Ac), an abundant sugar present in glycans in vertebrates and some bacteria, can be used as an energy source by several prokaryotes, including Escherichia coli. In solution, more than 99% of Neu5Ac is in cyclic form (≈92% beta-anomer and ≈7% alpha-anomer), whereas <0.5% is ... >> More
N-acetylneuraminate (Neu5Ac), an abundant sugar present in glycans in vertebrates and some bacteria, can be used as an energy source by several prokaryotes, including Escherichia coli. In solution, more than 99% of Neu5Ac is in cyclic form (≈92% beta-anomer and ≈7% alpha-anomer), whereas <0.5% is in the open form. The aldolase that initiates Neu5Ac metabolism in E. coli, NanA, has been reported to act on the alpha-anomer. Surprisingly, when we performed this reaction at pH 6 to minimize spontaneous anomerization, we found NanA and its human homolog NPL preferentially metabolize the open form of this substrate. We tested whether the E. coli Neu5Ac anomerase NanM could promote turnover, finding it stimulated the utilization of both beta and alpha-anomers by NanA in vitro. However, NanM is localized in the periplasmic space and cannot facilitate Neu5Ac metabolism by NanA in the cytoplasm in vivo. We discovered that YhcH, a cytoplasmic protein encoded by many Neu5Ac catabolic operons and belonging to a protein family of unknown function (DUF386), also facilitated Neu5Ac utilization by NanA and NPL and displayed Neu5Ac anomerase activity in vitro. YhcH contains Zn, and its accelerating effect on the aldolase reaction was inhibited by metal chelators. Remarkably, several transition metals accelerated Neu5Ac anomerization in the absence of enzyme. Experiments with E. coli mutants indicated that YhcH expression provides a selective advantage for growth on Neu5Ac. In conclusion, YhcH plays the unprecedented role of providing an aldolase with the preferred unstable open form of its substrate. << Less
J. Biol. Chem. 296:100699-100699(2021) [PubMed] [EuropePMC]
This publication is cited by 3 other entries.
Comments
RHEA:67740 part of RHEA:25233