There are two bifunctional aspartokinase / homoserine dehydrogenases, ThrA and MetL, in addition to a monofunctional aspartokinase, LysC . Transcription of aspartokinase genes is regulated by concentrations of the subsequently produced amino acids, lysine, threonine and methionine.
22.
As might be expected, the bifunctional enzymes from lower plants are larger ( 946 960 residues, 106 107 kDa ) than the monofunctional enzymes from higher plants ( 800 867 residues, 90 98 kDa ), although not by twice as much.
23.
This means firstly that a specialist enzyme ( monofunctional ) when evolved goes through a generalist stage ( multifunctional ), before becoming a specialist again presumably after gene duplication according to the IAD model and secondly that promiscuous activities are more plastic than the main activity.
24.
This electron-poor thiourea derivative enjoys the status of being a privileged catalyst and represents the benchmark for the design of a broad variety of explicit double hydrogen-bonding ( thio ) urea organocatalysts-achiral, and chiral as well as monofunctional and bifunctional representatives:
25.
Styrene is a low cost monomer and provides a fast cure, N-vinylpyrrolidone results in a material that is highly flexible when cured, has low toxicity, and acrylates are highly reactive, allowing for rapid cure rates, and are highly versatile with monomer functionality ranging from monofunctional to tetrafunctional.
26.
This entry represents various uracil-DNA glycosylases and related DNA glycosylases ( EC ), such as uracil-DNA glycosylase, thermophilic uracil-DNA glycosylase, G : T / U mismatch-specific DNA glycosylase ( Mug ), and single-strand selective monofunctional uracil-DNA glycosylase ( SMUG1 ).
27.
:: Rather a weak argument for a variety of reasons : It would be the rare man that doesn't also use his genitals for urination, so the religious view that morals demand that genitals be monofunctional ought to be a non-starter .-Nunh-huh 17 : 55, 21 December 2011 ( UTC)
28.
Phenanthriplatin forms monofunctional adducts with guanosine residues in the DNA . The large and hydrophobic nature of the phenanthridine ligand introduces steric hindrance within the major groove of the DNA, which impedes RNA polymerase II, a major protein used by the cell to transcribe DNA . Since transcription is essential for DNA synthesis and gene expression, phenanthriplatin inhibits both these processes in cancerous cells, ultimately inducing cellular apoptosis.
