2v2a
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L-RHAMNULOSE-1-PHOSPHATE ALDOLASE FROM ESCHERICHIA COLI (MUTANT E192A-K248G-R253A-E254A)
OverviewOverview
The enzyme l-rhamnulose-1-phosphate aldolase from Escherichia coli, participates in the degradation pathway of l-rhamnose, a ubiquitous, deoxy-hexose. It is a homotetramer of the rare C4-symmetric type with, N-terminal domains protruding like antennas from the main body. A mobility, analysis of the enzyme gave rise to the hypothesis that an anisotropic, thermal antenna motion may support the catalysis (Kroemer et al., Biochemistry 42, 10560, 2003). We checked this hypothesis by generating, four single mutants and one disulfide bridge that were designed to reduce, the mobility of the antenna domain without disturbing the chain-fold or, the active center. The catalytic rates of the mutants revealed activity, reductions that correlated well with the expected antenna fixation. Among, these mutants, K15W was crystallized, structurally elucidated, and used as, a guide for modeling the others. The structure confirmed the design, because the mutation introduced a tight nonpolar contact to a neighboring, subunit that fixed the antenna but did not affect the main chain. The, fixation was confirmed by a comparison of the anisotropic B-factors, describing the mobility of the domains. It turned out that the distinctly, anisotropic mobility of the wild-type antenna domain has become isotropic, in K15W, in agreement with the design. We suggest that, like K15W, the, other mutations also followed the design, validating the correlation, between antenna mobility and activity. This correlation suggests that the, domain mobility facilitates the reaction.
About this StructureAbout this Structure
2V2A is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as Rhamnulose-1-phosphate aldolase, with EC number 4.1.2.19 Known structural/functional Sites: , and . Full crystallographic information is available from OCA.
ReferenceReference
Antenna Domain Mobility and Enzymatic Reaction of l-Rhamnulose-1-phosphate Aldolase(,)., Grueninger D, Schulz GE, Biochemistry. 2008 Jan 15;47(2):607-14. Epub 2007 Dec 18. PMID:18085797
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- Escherichia coli
- Rhamnulose-1-phosphate aldolase
- Single protein
- Grueninger, D.
- Schulz, G.E.
- 13P
- ZN
- 2-ketose degradation
- Aldolase
- Bacterial l-rhamnose metabolism
- Class ii
- Cleavage of l-rhamnulose-1-phosphate to dihydroxyacetone phosphate
- Domain motion for mechanical support of catalysis
- Lyase
- Metal-binding
- Protein engineering
- Protein-protein interface
- Rare sugar
- Rhamnose metabolism
- Surface mutation
- Zinc
- Zinc enzyme