Activating Compound | Comment | Organism | Structure |
---|---|---|---|
VPS75 | histone chaperone, acts as activating subunit | Saccharomyces cerevisiae |
Crystallization (Comment) | Organism |
---|---|
molecular model of the complex between enzyme Rtt109 and histone chaperone Vps75 based on X-ray diffraction of crystals. The model reveals distinct negative electrostatic surfaces on an Rtt109 molecule that interface with complementary electropositive ends of a symmetrical Vps75 dimer. Rtt109 variants with interface point substitutions lack the ability to be fully activated by Vps75, yet these variants show no adverse effect on Asf1-dependent Rtt109 activities in vitro and in vivo. Molecular model with a 1:2 complex of Rtt109-Vps75 which acetylates a heterodimer of H3-H4 | Saccharomyces cerevisiae |
Protein Variants | Comment | Organism |
---|---|---|
E299K/E300K/D301K | similar activity toward H3 in comparison to wild-type enzyme, more than 10fold reduction in activation by chaperone Vps75 | Saccharomyces cerevisiae |
E374A/E378A | similar activity toward H3 in comparison to wild-type enzyme | Saccharomyces cerevisiae |
E374K/E378K | similar activity toward H3 in comparison to wild-type enzyme, more than 10fold reduction in activation by chaperone Vps75 | Saccharomyces cerevisiae |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0023 | - |
acetyl-CoA | wild-type, presence of 0.4 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.0039 | - |
acetyl-CoA | wild-type, presence of 0.2 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.0063 | - |
acetyl-CoA | wild-type, presence of 1 equivalent of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.0065 | - |
acetyl-CoA | wild-type, presence of 2 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.0065 | - |
acetyl-CoA | wild-type, presence of 8 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Saccharomyces cerevisiae | - |
- |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
acetyl-CoA + histone H3 | - |
Saccharomyces cerevisiae | CoA + acetylhistone H3 | - |
? | |
additional information | histone chaperone Vps75 acts as activiating subunit. The rate-determining step of the activated complex is the transfer of the acetyl group from acetyl-CoA to the acceptor lysine residue. Vps75 stimulates catalysis more than 250fold, not by contributing a catalytic base, but by stabilizing the catalytically active conformation of enzyme Rtt109 | Saccharomyces cerevisiae | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
Rtt109 | - |
Saccharomyces cerevisiae |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0011 | - |
acetyl-CoA | mutant E374A/E378A/D301K, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.0021 | - |
acetyl-CoA | mutant E374K/E378K, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.0023 | - |
acetyl-CoA | wild-type, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.0024 | - |
acetyl-CoA | mutant E374A/E378A, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.031 | - |
acetyl-CoA | mutant E374A/E378A/D301K, presence of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.035 | - |
acetyl-CoA | mutant E374K/E378K, presence of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.07 | - |
acetyl-CoA | wild-type, wild-type, presence of 0.2 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.08 | - |
acetyl-CoA | wild-type, presence of 0.4 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.16 | - |
acetyl-CoA | mutant E374A/E378A, presence of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.28 | - |
acetyl-CoA | wild-type, presence of 1 equivalent of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.48 | - |
acetyl-CoA | wild-type, presence of 2 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
0.62 | - |
acetyl-CoA | wild-type, presence of 8 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
18 | - |
acetyl-CoA | wild-type, presence of 0.2 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
35 | - |
acetyl-CoA | wild-type, presence of 0.4 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
44 | - |
acetyl-CoA | wild-type, presence of 1 equivalent of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
73 | - |
acetyl-CoA | wild-type, presence of 2 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae | |
97 | - |
acetyl-CoA | wild-type, presence of 8 equivalents of chaperone Vps75, pH 7.5, 25°C | Saccharomyces cerevisiae |