Switchgrass PviCAD1: understanding residues important for substrate preferences and activity.

Appl Biochem Biotechnol

USDA-ARS Grain, Forage, and Bioenergy Research Unit, University of Nebraska, 137 Keim Hall, Lincoln, NE 68583-0937, USA.

Published: November 2012

Cinnamyl alcohol dehydrogenase (CAD) catalyzes the final step in monolignol biosynthesis. Although plants contain numerous genes coding for CADs, only one or two CADs appear to have a primary physiological role in lignin biosynthesis. Much of this distinction appears to reside in a few key residues that permit reasonable catalytic rates on monolignal substrates. Here, several mutant proteins were generated using switchgrass wild type (WT) PviCAD1 as a template to understand the role of some of these key residues, including a proton shuttling HL duo in the active site. Mutated proteins displayed lowered or limited activity on cinnamylaldehydes and exhibited altered kinetic properties compared to the WT enzyme, suggesting that key residues important for efficient catalysis had been identified. We have also shown that a sorghum ortholog containing EW, instead of HL in its active site, displayed negligible activity against monolignals. These results indicate that lignifying CADs require a specific set of key residues for efficient activity against monolignals.

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12010-012-9843-0DOI Listing

Publication Analysis

Top Keywords

key residues
16
active site
8
residues efficient
8
activity monolignals
8
residues
5
switchgrass pvicad1
4
pvicad1 understanding
4
understanding residues
4
residues substrate
4
substrate preferences
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!