Science, Vol 268, Issue 5219, 1912-1914
Copyright © 1995 by American Association for the Advancement of Science
GTBP, a 160-kilodalton protein essential for mismatch-binding activity in human cells
F Palombo,
P Gallinari,
I Iaccarino,
T Lettieri,
M Hughes,
A D'Arrigo,
O Truong,
JJ Hsuan,
and
J Jiricny
Istituto di Ricerche di Biologia Molecolare P. Angeletti, Pomezia, Italy.
DNA mismatch recognition and binding in human cells has been thought to be mediated by the hMSH2 protein. Here it is shown that the mismatch-binding factor consists of two distinct proteins, the 100-kilodalton hMSH2 and a 160-kilodalton polypeptide, GTBP (for G/T binding protein). Sequence analysis identified GTBP as a new member of the MutS homolog family. Both proteins are required for mismatch-specific binding, a result consistent with the finding that tumor-derived cell lines devoid of either protein are also devoid of mismatch-binding activity.
