Biochemical and Structural Analysis of Aromatic Aldehyde Dehydrogenase B from Pseudomonas Syringae
Disciplines
Biochemistry | Cell Biology | Structural Biology
Abstract (300 words maximum)
The bacterial pathogen Pseudomonas syringae strain DC3000 suppresses host defenses and promotes infection of target plants by producing indole-3-acetic acid (IAA). Using microbial genome sequences and computational analysis tools, we previously identified three aldehyde dehydrogenases (ALDs) from P. syringae DC3000. Recent work demonstrated that NAD-dependent aldehyde dehydrogenase A (AldA) primarily produces pathogenic IAA from indole-3-acetaldehyde (IAAld). While each ALD shares a common reaction mechanism, their substrate specificity varies. As part of the 2024 Mentor Protégé Research Program in the College of Mathematics and Sciences at Kennesaw State University, our team is investigating the three-dimensional structures and biochemical activities of AldA and aldehyde dehydrogenase B (AldB) to better understand the role of active site residues and substrate specificity in each ALD. Using nickel-affinity chromatography, we expressed and purified His-tagged recombinant proteins to examine the effect of changes in the aldehyde substrate binding site. To further analyze the effects of mutations on activity and substrate specificity for IAAld and other aromatic aldehyde substrates, we will utilize steady-state kinetic analysis. The X-ray crystal structure of AldB, combined with biochemical analysis, provides valuable insights into the evolution of enzyme function and molecular architecture in the IAA biosynthetic pathway of the bacterial pathogen P. syringae.
Academic department under which the project should be listed
CSM - Molecular and Cellular Biology
Primary Investigator (PI) Name
Soon Goo Lee
Biochemical and Structural Analysis of Aromatic Aldehyde Dehydrogenase B from Pseudomonas Syringae
The bacterial pathogen Pseudomonas syringae strain DC3000 suppresses host defenses and promotes infection of target plants by producing indole-3-acetic acid (IAA). Using microbial genome sequences and computational analysis tools, we previously identified three aldehyde dehydrogenases (ALDs) from P. syringae DC3000. Recent work demonstrated that NAD-dependent aldehyde dehydrogenase A (AldA) primarily produces pathogenic IAA from indole-3-acetaldehyde (IAAld). While each ALD shares a common reaction mechanism, their substrate specificity varies. As part of the 2024 Mentor Protégé Research Program in the College of Mathematics and Sciences at Kennesaw State University, our team is investigating the three-dimensional structures and biochemical activities of AldA and aldehyde dehydrogenase B (AldB) to better understand the role of active site residues and substrate specificity in each ALD. Using nickel-affinity chromatography, we expressed and purified His-tagged recombinant proteins to examine the effect of changes in the aldehyde substrate binding site. To further analyze the effects of mutations on activity and substrate specificity for IAAld and other aromatic aldehyde substrates, we will utilize steady-state kinetic analysis. The X-ray crystal structure of AldB, combined with biochemical analysis, provides valuable insights into the evolution of enzyme function and molecular architecture in the IAA biosynthetic pathway of the bacterial pathogen P. syringae.