Abstract
We report the crystal structures of the phosporylated pyruvate dehydrogenase (E1p) component of the human pyruvate dehydrogenase complex (PDC). The complete phosphorylation at Ser264-α (site 1) of a variant E1p protein was achieved using robust pyruvate dehydrogenase kinase 4 free of the PDC core. We show that unlike its unmodified counterpart, the presence of a phosphoryl group at Ser264-α prevents the cofactor thiamine diphosphate-induced ordering of the two loops carrying the three phosphorylation sites. The disordering of these phosphorylation loops is caused by a previously unrecognized steric clash between the phosphoryl group at site 1 and a nearby Ser266-α, which nullifies a hydrogen-bonding network essential for maintaining the loop conformations. The disordered phosphorylation loops impede the binding of lipoyl domains of the PDC core to E1p, negating the reductive acetylation step. This results in the disruption of the substrate channeling in the PDC, leading to the inactivation of this catalytic machine.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1849-1859 |
| Number of pages | 11 |
| Journal | Structure |
| Volume | 16 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 12 2008 |
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Keywords
- PROTEINS
ASJC Scopus subject areas
- Molecular Biology
- Structural Biology
Cite this
Structural Basis for Inactivation of the Human Pyruvate Dehydrogenase Complex by Phosphorylation : Role of Disordered Phosphorylation Loops. / Kato, Masato; Wynn, R. Max; Chuang, Jacinta L.; Tso, Shih Chia; Machius, Mischa; Li, Jun; Chuang, David T.
In: Structure, Vol. 16, No. 12, 12.12.2008, p. 1849-1859.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Structural Basis for Inactivation of the Human Pyruvate Dehydrogenase Complex by Phosphorylation
T2 - Role of Disordered Phosphorylation Loops
AU - Kato, Masato
AU - Wynn, R. Max
AU - Chuang, Jacinta L.
AU - Tso, Shih Chia
AU - Machius, Mischa
AU - Li, Jun
AU - Chuang, David T.
PY - 2008/12/12
Y1 - 2008/12/12
N2 - We report the crystal structures of the phosporylated pyruvate dehydrogenase (E1p) component of the human pyruvate dehydrogenase complex (PDC). The complete phosphorylation at Ser264-α (site 1) of a variant E1p protein was achieved using robust pyruvate dehydrogenase kinase 4 free of the PDC core. We show that unlike its unmodified counterpart, the presence of a phosphoryl group at Ser264-α prevents the cofactor thiamine diphosphate-induced ordering of the two loops carrying the three phosphorylation sites. The disordering of these phosphorylation loops is caused by a previously unrecognized steric clash between the phosphoryl group at site 1 and a nearby Ser266-α, which nullifies a hydrogen-bonding network essential for maintaining the loop conformations. The disordered phosphorylation loops impede the binding of lipoyl domains of the PDC core to E1p, negating the reductive acetylation step. This results in the disruption of the substrate channeling in the PDC, leading to the inactivation of this catalytic machine.
AB - We report the crystal structures of the phosporylated pyruvate dehydrogenase (E1p) component of the human pyruvate dehydrogenase complex (PDC). The complete phosphorylation at Ser264-α (site 1) of a variant E1p protein was achieved using robust pyruvate dehydrogenase kinase 4 free of the PDC core. We show that unlike its unmodified counterpart, the presence of a phosphoryl group at Ser264-α prevents the cofactor thiamine diphosphate-induced ordering of the two loops carrying the three phosphorylation sites. The disordering of these phosphorylation loops is caused by a previously unrecognized steric clash between the phosphoryl group at site 1 and a nearby Ser266-α, which nullifies a hydrogen-bonding network essential for maintaining the loop conformations. The disordered phosphorylation loops impede the binding of lipoyl domains of the PDC core to E1p, negating the reductive acetylation step. This results in the disruption of the substrate channeling in the PDC, leading to the inactivation of this catalytic machine.
KW - PROTEINS
UR - http://www.scopus.com/inward/record.url?scp=57049114930&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=57049114930&partnerID=8YFLogxK
U2 - 10.1016/j.str.2008.10.010
DO - 10.1016/j.str.2008.10.010
M3 - Article
C2 - 19081061
AN - SCOPUS:57049114930
VL - 16
SP - 1849
EP - 1859
JO - Structure with Folding & design
JF - Structure with Folding & design
SN - 0969-2126
IS - 12
ER -