alexa Structure of protocatechuate 3,4-dioxygenase from Pseudomonas aeruginosa at 2.15 A resolution.
Environmental Sciences

Environmental Sciences

Journal of Bioremediation & Biodegradation

Author(s): Ohlendorf DH, Orville AM, Lipscomb JD

Abstract Share this page

Abstract Protocatechuate 3,4-dioxygenase catalyzes the aromatic ring cleavage of 3,4-dihydroxybenzoate by incorporating both atoms of molecular oxygen to yield beta-carboxy-cis,cis-muconate. The structure of this metalloenzyme from Pseudomonas aeruginosa (now reclassified as P. putida) has been refined to an R-factor of 0.172 to 2.15 A resolution. The structure is a highly symmetric (alpha beta Fe3+)12 aggregate with a root-mean-square (r.m.s.) difference of 0.18 A among symmetry-related atoms. The tertiary structure of the two polypeptides (alpha and beta) are highly homologous (r.m.s. difference of 1.05 A over 127 C alpha atoms), suggesting that the ancestral enzyme was originally a homodimer with two active sites. Indeed, a non-functional, vestigial active site retains many of the properties of the functional active site but does not bind iron. The coordination geometry of the non-heme iron catalytic cofactor can best be described as trigonal bipyramidal with Tyr447 (147 beta) and His462 (162 beta) serving as axial ligands, and Tyr408 (108 beta), His460 (160 beta) and Wat837 serving as equitorial ligands. The active site environment has a number of basic residues that may promote binding of the acidic substrate. Within the putative active site cavity which is located between alpha and beta chains, five approximately coplanar solvent molecules suggest a position for the planar substrate Trp449 (149 beta), Ile491 (191 beta), defined by Gly14 (14 alpha) and Pro15 (15 alpha). In this position the guanidino group of Arg457 (157 beta) would be buried by the substrate, suggesting a functional role in catalysis. This article was published in J Mol Biol and referenced in Journal of Bioremediation & Biodegradation

Relevant Expert PPTs

Relevant Speaker PPTs

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

Agri & Aquaculture Journals

Dr. Krish

1-702-714-7001Extn: 9040

Biochemistry Journals

Datta A

1-702-714-7001Extn: 9037

Business & Management Journals


1-702-714-7001Extn: 9042

Chemistry Journals

Gabriel Shaw

1-702-714-7001Extn: 9040

Clinical Journals

Datta A

1-702-714-7001Extn: 9037

Engineering Journals

James Franklin

1-702-714-7001Extn: 9042

Food & Nutrition Journals

Katie Wilson

1-702-714-7001Extn: 9042

General Science

Andrea Jason

1-702-714-7001Extn: 9043

Genetics & Molecular Biology Journals

Anna Melissa

1-702-714-7001Extn: 9006

Immunology & Microbiology Journals

David Gorantl

1-702-714-7001Extn: 9014

Materials Science Journals

Rachle Green

1-702-714-7001Extn: 9039

Nursing & Health Care Journals

Stephanie Skinner

1-702-714-7001Extn: 9039

Medical Journals

Nimmi Anna

1-702-714-7001Extn: 9038

Neuroscience & Psychology Journals

Nathan T

1-702-714-7001Extn: 9041

Pharmaceutical Sciences Journals

Ann Jose

1-702-714-7001Extn: 9007

Social & Political Science Journals

Steve Harry

1-702-714-7001Extn: 9042

© 2008- 2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version