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PDBsum entry 6drb
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References listed in PDB file
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Key reference
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Title
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A yoph ptp1b chimera shows the importance of the wpd-Loop sequence to the activity, Structure, And dynamics of protein tyrosine phosphatases.
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Authors
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G.Moise,
Y.Morales,
V.Beaumont,
T.Caradonna,
J.P.Loria,
S.J.Johnson,
A.C.Hengge.
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Ref.
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Biochemistry, 2018,
57,
5315-5326.
[DOI no: ]
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PubMed id
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Abstract
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To study factors that affect WPD-loop motion in protein tyrosine phosphatases
(PTPs), a chimera of PTP1B and YopH was created by transposing the WPD loop from
PTP1B to YopH. Several subsequent mutations proved to be necessary to obtain a
soluble, active enzyme. That chimera, termed chimera 3, retains productive
WPD-loop motions and general acid catalysis with a pH dependency similar to that
of the native enzymes. Kinetic isotope effects show the mechanism and transition
state for phosphoryl transfer are unaltered. Catalysis of the chimera is slower
than that of either of its parent enzymes, although its rate is comparable to
those of most native PTPs. X-ray crystallography and nuclear magnetic resonance
were used to probe the structure and dynamics of chimera 3. The chimera's
structure was found to sample an unproductive hyper-open conformation of its WPD
loop, a geometry that has not been observed in either of the parents or in other
native PTPs. The reduced catalytic rate is attributed to the protein's sampling
of this conformation in solution, reducing the fraction in the catalytically
productive loop-closed conformation.
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