Faculty Collaboration Database

The urea carboxylase and allophanate hydrolase activities of urea amidolyase are functionally independent. Protein Sci 2016 Oct;25(10):1812-24

Date

07/28/2016

Pubmed ID

27452902

Pubmed Central ID

PMC5029531

DOI

10.1002/pro.2990

Scopus ID

2-s2.0-84988377991 (requires institutional sign-in at Scopus site)   10 Citations

Abstract

Urea amidolyase (UAL) is a multifunctional biotin-dependent enzyme that contributes to both bacterial and fungal pathogenicity by catalyzing the ATP-dependent cleavage of urea into ammonia and CO2 . UAL is comprised of two enzymatic components: urea carboxylase (UC) and allophanate hydrolase (AH). These enzyme activities are encoded on separate but proximally related genes in prokaryotes while, in most fungi, they are encoded by a single gene that produces a fusion enzyme on a single polypeptide chain. It is unclear whether the UC and AH activities are connected through substrate channeling or other forms of direct communication. Here, we use multiple biochemical approaches to demonstrate that there is no substrate channeling or interdomain/intersubunit communication between UC and AH. Neither stable nor transient interactions can be detected between prokaryotic UC and AH and the catalytic efficiencies of UC and AH are independent of one another. Furthermore, an artificial fusion of UC and AH does not significantly alter the AH enzyme activity or catalytic efficiency. These results support the surprising functional independence of AH from UC in both the prokaryotic and fungal UAL enzymes and serve as an important reminder that the evolution of multifunctional enzymes through gene fusion events does not always correlate with enhanced catalytic function.

Author List

Lin Y, Boese CJ, St Maurice M

Author

Martin St. Maurice PhD Associate Professor in the Biology department at Marquette University

MESH terms used to index this publication - Major topics in bold

Allophanate Hydrolase
Bacterial Proteins
Carbon-Nitrogen Ligases
Catalysis
Pseudomonas syringae
Saccharomyces cerevisiae
Saccharomyces cerevisiae Proteins