4Z17

Thermostable enolase from Chloroflexus aurantiacus

Summary for 4Z17

• Entry DOI: 10.2210/pdb4z17/pdb
• Related: 4YWS 4Z1Y
• Descriptor: Enolase, MAGNESIUM ION, PHOSPHOENOLPYRUVATE, ... (4 entities in total)
• Functional Keywords: enolase, thermostability, thermophilic origin, phylogeny, lyase
• Biological source: Chloroflexus aurantiacus (strain ATCC 29366 / DSM 635 / J-10-fl)
• Total number of polymer chains: 2
• Total formula weight: 92325.03

Authors

Zadvornyy, O.A.,Peters, J.W. (deposition date: 2015-03-26, release date: 2015-07-01, Last modification date: 2023-09-27)

Primary citation

Zadvornyy, O.A.,Boyd, E.S.,Posewitz, M.C.,Zorin, N.A.,Peters, J.W.
Biochemical and Structural Characterization of Enolase from Chloroflexus aurantiacus: Evidence for a Thermophilic Origin.
Front Bioeng Biotechnol, 3:74-74, 2015

PubMed Abstract: Enolase catalyzes the conversion of 2-phosphoglycerate to phosphoenolpyruvate during both glycolysis and gluconeogenesis, and is required by all three domains of life. Here, we report the purification and biochemical and structural characterization of enolase from Chloroflexus aurantiacus, a thermophilic anoxygenic phototroph affiliated with the green non-sulfur bacteria. The protein was purified as a homodimer with a subunit molecular weight of 46 kDa. The temperature optimum for enolase catalysis was 80°C, close to the measured thermal stability of the protein which was determined to be 75°C, while the pH optimum for enzyme activity was 6.5. The specific activities of purified enolase determined at 25 and 80°C were 147 and 300 U mg(-1) of protein, respectively. K m values for the 2-phosphoglycerate/phosphoenolpyruvate reaction determined at 25 and 80°C were 0.16 and 0.03 mM, respectively. The K m values for Mg(2+) binding at these temperatures were 2.5 and 1.9 mM, respectively. When compared to enolase from mesophiles, the biochemical and structural properties of enolase from C. aurantiacus are consistent with this being thermally adapted. These data are consistent with the results of our phylogenetic analysis of enolase, which reveal that enolase has a thermophilic origin.

PubMed: 26082925
DOI: 10.3389/fbioe.2015.00074

Experimental method

X-RAY DIFFRACTION (2.65 Å)