Acetolactate synthase

Overview

Diagram of Acetolactate Synthase

Acetolactate synthase (ALS), also known as acetohydroxyacid synthase, is an enzyme that plays a crucial role in the biosynthesis of branched-chain amino acids, such as valine, leucine, and isoleucine. This enzyme catalyzes the first step in the pathway, which involves the condensation of two molecules of pyruvate to form acetolactate.

Function

Acetolactate synthase is responsible for the conversion of pyruvate into acetolactate, which is a key intermediate in the synthesis of branched-chain amino acids. This reaction is essential for the production of these amino acids, which are vital for protein synthesis and various metabolic processes in plants and microorganisms.

Structure

ALS is a multi-subunit enzyme that requires the presence of cofactors such as thiamine pyrophosphate (TPP) and flavin adenine dinucleotide (FAD) for its activity. The enzyme is typically composed of large and small subunits, which work together to facilitate the catalytic process.

Inhibition

Acetolactate synthase is a target for several classes of herbicides, including sulfonylureas and imidazolinones. These herbicides inhibit the enzyme, leading to the disruption of amino acid synthesis and ultimately causing plant death. This makes ALS a critical target for agricultural weed control.

Applications

The study of acetolactate synthase is important in both agriculture and medicine. In agriculture, understanding ALS can lead to the development of herbicide-resistant crops. In medicine, insights into ALS function can contribute to the development of antibiotics, as the enzyme is present in many pathogenic microorganisms.

Related pages

• Branched-chain amino acid
• Enzyme inhibition
• Herbicide
• Pyruvate