M. Hildebrandt et al., A HUMAN NDP-KINASE-B SPECIFICALLY BINDS SINGLE-STRANDED POLY-PYRIMIDINE SEQUENCES, Nucleic acids research, 23(19), 1995, pp. 3858-3864
Recently, a DNA binding protein 'PUF' was purified that binds to a pol
y-pyrimidine rich element in the human c-myc promoter. Cloning of the
corresponding gene surprisingly identified this putative transcription
factor as isoform B of the enzyme nucleoside diphosphate kinase (NDPK
-B) [Postel et al, (1993) Science, 261, 478-480], the product of the p
otential metastasis suppressor gene nm23-H2. Using different recombina
nt NDP kinases, we demonstrate by electrophoretic mobility shift analy
sis (EMSA) that the NDP kinase DNA binding properties are predominantl
y observed with human isoform B. Unlike typical DNA binding proteins t
hat are involved in transcriptional regulation, binding occurs to sing
le-stranded DNA rather than to a double-stranded oligonucleotide. As a
consequence, complexes of single-stranded DNA and NDPK-B are generate
d from double-stranded oligonucleotide hybrids in an ATP independent m
anner. In addition to the c-myc element, NDPK-B is binding in vitro to
a variety of poly-pyrimidine rich sequences including dC or dT homo-o
ligomers, (CT)n dinucleotide repeats, the initiator region of the Aden
ovirus major late promoter and even poly-pyrimidine rich RNAs. The pos
sible consequences of these findings in understanding the multiple rol
es of NDP kinase are discussed.