Effectors of Escherichia coli aspartate transcarbamoylase differentially perturb aspartate binding rather than the T-R transition.
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چکیده
منابع مشابه
Effectors of Escherichia coli aspartate transcarbamoylase differentially perturb aspartate binding rather than the T-R transition.
New systematic methods developed for equilibrium isotope exchange kinetics have been used to analyze the effects of activator ATP and inhibitor CTP with Escherichia coli aspartate transcarbamoylase. This indepth approach requires (a) variation of [modifier] with fixed subsaturating levels of substrates, and (b) variation of at least three combinations of reactant-product pairs in constant ratio...
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Reaction microcalorimetry and potentiometry have been used to define the thermodynamics of assembly of Escherichia coli aspartate transcarbamoylase (aspartate carbamoyltransferase, carbamoylphosphate:L-aspartate carbamoyltransferase, EC 2.1.3.2) from its catalytic and regulatory subunits and the linkage between assembly and proton binding. Over the pH range 7-9.5 and the temperature range 15-30...
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participate in different ways in the assembly of the complex. The positioning of a subunit in the complex may be crucial to its function. The dynamic equilibrium between various assembly states of a heteropolymer cannot be treated as if the assembly involves structurally homogeneous elements whose association reactions can be described by a single interaction constant. On the contrary, each sta...
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Here we report the first use of disulfide bond formation to stabilize the R allosteric structure of Escherichia coli aspartate transcarbamoylase. In the R allosteric state, residues in the 240s loop from two catalytic chains of different subunits are close together, whereas in the T allosteric state they are far apart. By substitution of Ala-241 in the 240s loop of the catalytic chain with cyst...
متن کاملThe contribution of individual interchain interactions to the stabilization of the T and R states of Escherichia coli aspartate transcarbamoylase.
Stabilization of the T and R allosteric states of Escherichia coli aspartate transcarbamoylase is governed by specific intra- and interchain interactions. The six interchain interactions between Glu-239 in one catalytic chain of one catalytic trimer with both Lys-164 and Tyr-165 of a different catalytic chain in the other catalytic trimer have been shown to be involved in the stabilization of t...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1988
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)68905-7