Usually enzyme complexes make multistep processes easier by catalyzing sequential reactions in which the product of one enzyme becomes the substrate for the next. However this is a particular and very interesting case of a complex formed by a different kind of enzymes. This 1.6 megadalton multi-enzyme complex from Bacillus subtilis is composed of two enzymes catalyzing opposite ('counter-enzymes') rather than sequential reactions: glutamate synthase (GltAB) and glutamate dehydrogenase (GudB), which make and break glutamate, respectively. In vivo and in vitro studies show that the primary role of complex formation is to inhibit the activity of GudB. The complex exhibits unusual oscillatory progress curves and is necessary for both planktonic growth, in glutamate-limiting conditions, and for biofilm growth, in glutamate-rich media. The regulation of a key metabolic enzyme by complexing with its counter enzyme may thus enable cell growth under fluctuating glutamate concentrations. Here you can see the structure of this bacterial complex determined by cryoEM (PDB code: 7MFT)
#molecularart ... #immolecular ... #complex ... #counteracting ... #enzyme ... #glutamate ... #bacillus ... #cryoem
Enzyme complex rendered with @proteinimaging and depicted with @corelphotopaint
#molecularart ... #immolecular ... #complex ... #counteracting ... #enzyme ... #glutamate ... #bacillus ... #cryoem
Enzyme complex rendered with @proteinimaging and depicted with @corelphotopaint
