Biochemical and structural analysis of aromatic aldehyde dehydrogenase B from Pseudomonas syringae DC3000
Disciplines
Cell Biology | Microbiology
Abstract (300 words maximum)
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) mainly produces pathogenic IAA from indole-3-acetaldehyde (IAAld). Even though each ALD shares a common reaction mechanism, substrate specificity varies. As part of the 2024 Mentor Protégé Research Program, 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 of 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 and biochemical analysis provide insights into the evolution of enzyme 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 DC3000
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) mainly produces pathogenic IAA from indole-3-acetaldehyde (IAAld). Even though each ALD shares a common reaction mechanism, substrate specificity varies. As part of the 2024 Mentor Protégé Research Program, 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 of 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 and biochemical analysis provide insights into the evolution of enzyme and molecular architecture in the IAA biosynthetic pathway of the bacterial pathogen P. syringae.