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Crystal structure of the Ca 2+ ‐form and Ca 2+ ‐binding kinetics of metastasis‐associated protein, S100A4
Author(s) -
Gingras Alexandre R.,
Basran Jaswir,
Prescott Andrew,
Kriajevska Marina,
Bagshaw Clive R.,
Barsukov Igor L.
Publication year - 2008
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2008.04.017
Subject(s) - kinetics , extracellular , chemistry , biophysics , intracellular , fluorescence , tyrosine , chemical kinetics , crystal structure , crystallography , biochemistry , biology , physics , quantum mechanics
S100A4 takes part in control of tumour cell migration and contributes to metastatic spread in in vivo models. In the active dimeric Ca 2+ ‐bound state it interacts with multiple intracellular targets. Conversely, oligomeric forms of S100A4 are linked with the extracellular function of this protein. We report the 1.5 Å X‐ray crystal structure of Ca 2+ ‐bound S100A4 and use it to identify the residues involved in target recognition and to derive a model of the oligomeric state. We applied stopped‐flow analysis of tyrosine fluorescence to derive kinetics of S100A4 activation by Ca 2+ ( k on = 3.5 μM −1 s −1 , k off = 20 s −1 ).