Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

The Pro Region N-Terminal Domain Provides Specific Interactions Required for Catalysis of R-Lytic Protease Folding

Summary: The Pro Region N-Terminal Domain Provides Specific Interactions Required for
Catalysis of R-Lytic Protease Folding
Erin L. Cunningham, Ted Mau, Stephanie M. E. Truhlar, and David A. Agard*,,|
The Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, Graduate Group in Biophysics, and
Program in Chemistry and Chemical Biology, UniVersity of California at San Francisco, San Francisco, California 94143-0448
ReceiVed March 18, 2002; ReVised Manuscript ReceiVed May 14, 2002
ABSTRACT: The extracellular bacterial protease, R-lytic protease (RLP), is synthesized with a large, two-
domain pro region (Pro) that catalyzes the folding of the protease to its native conformation. In the absence
of its Pro folding catalyst, RLP encounters a very large folding barrier (G ) 30 kcal mol-1) that effectively
prevents the protease from folding (t1/2 of folding ) 1800 years). Although homology data, mutational
studies, and structural analysis of the Pro,RLP complex suggested that the Pro C-terminal domain (Pro
C-domain) serves as the minimum "foldase" unit responsible for folding catalysis, we find that the Pro
N-terminal domain (Pro N-domain) is absolutely required for RLP folding. Detailed kinetic analysis of
Pro N-domain point mutants and a complete N-domain deletion reveal that the Pro N-domain both provides
direct interactions with RLP that stabilize the folding transition state and confers stability to the Pro
C-domain. The Pro N- and C-domains make conflicting demands upon native RLP binding that are
alleviated in the optimized interface of the folding transition state complex. From these studies, it appears
that the extremely high RLP folding barrier necessitates the presence of both the Pro domains; however,
RLP homologues with less demanding folding barriers may not require both domains, thus possibly
explaining the wide variation in the pro region size of related pro-proteases.


Source: Agard, David - Department of Biochemistry and Biophysics, University of California at San Francisco


Collections: Biotechnology; Biology and Medicine