A novel putative transcription factor protein MYT2 that preferentially binds supercoiled DNA and induces DNA synthesis in quiescent cells.
Myelin transcription factor 2 (MYT2), a putative transcription factor found in the human central nervous system, was cloned from an expression cDNA library from human T-cells. MYT2 shares weak similarity to bacterial type I topoisomerases and shares 63% sequence identity to a replicase from Leuconostoc mesenteroides. MYT2 preferentially binds supercoiled DNA (scDNA). Incubation of MYT2 and scDNA at or above equal molar ratios generated topoisomer-like patterns that were abolished by deproteination. Thus, MYT2 appears to relax scDNA via a non-enzymatic mechanism. The banding pattern of MYT2-scDNA complexes was shown to be quantisized, saturable and sequence-independent. Microinjection of MYT2 mRNA induced G(o) growth-arrested NIH 3T3 cells to enter the S phase of the cell cycle.
Shao
W
W
Structural Biochemistry Program, SAIC Frederick, National Cancer Institute-Frederick Cancer Research and Development Center, Frederick, MD 21702, USA. wei.shao@celera.com
Lee
A Y
AY
Gulnik
S
S
Gustchina
E
E
Liu
Y L
YL
Kung
H
H
Erickson
J W
JW
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004247:DNA / Q000096:biosynthesis* / Q000378:metabolism; D004264:DNA Topoisomerases, Type I / Q000378:metabolism; D004278:DNA, Superhelical / Q000378:metabolism* / Q000648:ultrastructure; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D051379:Mice; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism
D004278:DNA, Superhelical; D004268:DNA-Binding Proteins; C116002:MYT2 protein, human; D014157:Transcription Factors; D004247:DNA; D004264:DNA Topoisomerases, Type I