The structural basis for the perturbed pKa of the catalytic base in 4-oxalocrotonate tautomerase: kinetic and structural effects of mutations of Phe-50

Biochemistry
R M CzerwinskiC P Whitman

Abstract

The amino-terminal proline of 4-oxalocrotonate tautomerase (4-OT) functions as the general base catalyst in the enzyme-catalyzed isomerization of beta,gamma-unsaturated enones to their alpha,beta-isomers because of its unusually low pK(a) of 6.4 +/- 0.2, which is 3 units lower than that of the model compound, proline amide. Recent studies show that this abnormally low pK(a) is not due to the electrostatic effects of nearby cationic residues (Arg-11, Arg-39, and Arg-61) [Czerwinski, R. M., Harris, T. K., Johnson, Jr., W. H., Legler, P. M., Stivers, J. T., Mildvan, A. S., and Whitman, C. P. (1999) Biochemistry 38, 12358-12366]. Hence, it may result solely from a low local dielectric constant of 14.7 +/- 0.8 at the otherwise hydrophobic active site. Support for this mechanism comes from the study of mutants of the active site Phe-50, which is 5.8 A from Pro-1 and is one of 12 apolar residues within 9 A of Pro-1. Replacing Phe-50 with Tyr does not significantly alter k(cat) or K(m) and results in a pK(a) of 6.0 +/- 0.1 for Pro-1 as determined by (15)N NMR spectroscopy, comparable to that observed for wild type. (1)H-(15)N HSQC and 3D (1)H-(15)N NOESY HSQC spectra of the F50Y mutant demonstrate its conformation to be very similar to...Continue Reading

References

Jan 1, 1986·Annual Review of Biophysics and Biophysical Chemistry·D M EngelmanA Goldman
Nov 1, 1995·Journal of Biomolecular NMR·F DelaglioA Bax
Sep 1, 1994·Journal of Biomolecular NMR·B A Johnson, R A Blevins

❮ Previous
Next ❯

Citations

Dec 17, 2003·Current Opinion in Structural Biology·René M de Jong, Bauke W Dijkstra
Nov 8, 2002·Journal of Molecular Biology·Gail J BartlettJanet M Thornton
Nov 17, 2011·Journal of the American Chemical Society·Garrett B GohCharles L Brooks
Apr 15, 2008·Nature Structural & Molecular Biology·Elsa D GarcinJohn A Tainer
Jan 11, 2014·Journal of the American Chemical Society·Marta Diez-CastellnouPaolo Scrimin
Oct 18, 2013·Molecules : a Journal of Synthetic Chemistry and Natural Product Chemistry·Jingjing CuiEdwin A Lewis
Oct 2, 2007·Bioorganic Chemistry·Robin Sevastik, Fahmi Himo
May 23, 2012·Chembiochem : a European Journal of Chemical Biology·Ellen ZandvoortGerrit J Poelarends
May 8, 2013·Chembiochem : a European Journal of Chemical Biology·Bert-Jan BaasGerrit J Poelarends
Jul 9, 2013·Archives of Biochemistry and Biophysics·Cassidy R TerrellDavid W Hoffman
Jan 1, 2012·Computational and Structural Biotechnology Journal·Perrin Baker, Stephen Y K Seah
Sep 16, 2014·Archives of Biochemistry and Biophysics·Jamison P HuddlestonChristian P Whitman
Mar 10, 2017·Organic & Biomolecular Chemistry·Mehran RahimiGerrit J Poelarends
Dec 1, 2017·The Journal of Biological Chemistry·Rebecca DavidsonPatricia C Babbitt
Aug 31, 2017·Angewandte Chemie·Jonathan PettingerMatthew D Cheeseman
Jul 18, 2018·Proceedings of the National Academy of Sciences of the United States of America·Charlotte M MitonFlorian Hollfelder
Nov 13, 2020·International Journal of Biological Macromolecules·Atala B JenaJagnehswar Dandapat
Dec 19, 2020·Chemosphere·Mark StanojevićMarija Sollner Dolenc
Sep 12, 2006·Inorganic Chemistry·Graham T T GibsonR S Brown
Apr 21, 2005·Journal of the American Chemical Society·Norman MetanisPhilip E Dawson
Jun 18, 2021·Journal of Chemical Information and Modeling·Zeynep Pinar HaslakGerald Monard
Aug 11, 2021·Journal of Chemical Information and Modeling·Nicole BalascoLuigi Vitagliano
Jun 30, 2019·The Journal of Physical Chemistry. B·Luka BilićBorislav Kovačević
Dec 13, 2019·The Journal of Organic Chemistry·Rosaura Padilla-SalinasHang Yin

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.