Related Experiment Video
Updated: Aug 12, 2026

Functional Complementation Analysis (FCA): A Laboratory Exercise Designed and Implemented to Supplement the Teaching of Biochemical Pathways
Published on: June 24, 2016
Physical and enzymological interaction of Bacillus subtilis proteins required for de novo pyridoxal 5'-phosphate
1Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA. bbelit02@granite.tufts.edu
Abstract:
Bacillus subtilis synthesizes pyridoxal 5'-phosphate, the active form of vitamin B(6), by a poorly characterized pathway involving the yaaD and yaaE genes. The pdxS (yaaD) mutant was confirmed to be a strict B(6) auxotroph, but the pdxT (yaaE) mutant turned out to be a conditional auxotroph depending on the availability of ammonium in the growth medium. The PdxS and PdxT proteins copurified during affinity chromatography and apparently form a complex that has glutaminase activity. PdxS and PdxT appear to encode the synthase and glutaminase subunits, respectively, of a glutamine amidotransferase of as-yet-unknown specificity essential for B(6) biosynthesis.
Related Concept Videos
Ribosomal RNA Synthesis
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Introduction to Mechanisms of Enzyme Catalysis
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Biosynthesis in Bacteria
Amino Acid Biosynthetic Pathways
Biosynthesis of Nucleic Acids

