3IA4

Moritella profunda dihydrofolate reductase (DHFR) in complex with NADPH and methotrexate (MTX)

Summary for 3IA4

• Entry DOI: 10.2210/pdb3ia4/pdb
• Related: 3IA5
• Descriptor: Dihydrofolate reductase, NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE, METHOTREXATE, ... (4 entities in total)
• Functional Keywords: dhfr dihydrofolate reductase, nadph, methotrexate, oxidoreductase
• Biological source: Moritella profunda
• Total number of polymer chains: 4
• Total formula weight: 78034.52

Authors

Levy, C. (deposition date: 2009-07-13, release date: 2009-07-21, Last modification date: 2024-02-21)

Primary citation

Hay, S.,Evans, R.M.,Levy, C.,Loveridge, E.J.,Wang, X.,Leys, D.,Allemann, R.K.,Scrutton, N.S.
Are the Catalytic Properties of Enzymes from Piezophilic Organisms Pressure Adapted?
Chembiochem, 10:2348-2353, 2009

PubMed Abstract: We report the crystal structure of dihydrofolate reductase (DHFR) from the psychropiezophilic bacterium Moritella profunda, which was isolated from the deep ocean at 2 degrees C and 280 bar. The structure is typical of a chromosomal DHFR and we were unable to identify any obvious structural features that would suggest pressure adaptation. In particular, the core regions of the enzyme are virtually identical to those of the DHFR from the mesophile Escherichia coli. The steady-state rate at pH 9, which is limited by hydride transfer at atmospheric pressure, is roughly constant between 1 and 750 bar, falling at higher pressures. However, the value of K(M) increases with increasing pressure, and as a result k(cat)/K(M) decreases over the entire pressure range studied. Isotope effect studies showed that increasing the pressure causes a change in the rate-limiting step of the reaction. We therefore see no evidence of pressure adaptation in either the structure or the activity of this enzyme.

PubMed: 19681091
DOI: 10.1002/cbic.200900367

Experimental method

X-RAY DIFFRACTION (1.7 Å)