Purification of the major histocompatibility complex class I transcription factor H2TF1: The full-length product of the nfkb2 gene

H2TF1 is a ubiquitous major histocompatibility complex (MHC) class I-specific transcription factor, which binds to the palindromic κB enhancer site upstream of MHC class I genes. Here we report that H2TF1 consists of a polypeptide with relative molecular mass 110,000, that corresponds to the predicted 100-kDa product (NF-κB2 p 100) encoded by the candidate proto-oncogene nfkb2 (lyt-10). H2TF1 was purified by a novel affinity chromatography method and identified as the NF-κB2 p100 polypeptide by peptide sequencing as well as by reactivity with a specific antiserum. Purified H2TF1 binds the MHC κB site with high affinity (K_D = 3 × 10^-11 M), in contrast with previous reports that NF-κB2 p100 did not bind DNA. * This work was supported by fellowship support of the Division of Hematology/Oncology, Brigham and Women's Hospital, a grant from the Medical Research Council of Canada, National Cancer Institute Grant K08-CA-01562-01 (to D. A. P.), United States Public Health Service Grant P01-CA42063, a cooperative agreement (CDR-8803014) from the National Science Foundation (to P. A. S.), by Cancer Center Support (core) Grant P30-CA14051 from the National Cancer Institute, a Liebig scholarship from the Fond Der Chemischen Industrie West Germany (to P. E.), a grant from the Harvard Medical School/Hoffman-La Roche Institute of Chemistry and Medicine, a Searle Scholar Award, a National Science Foundation Presidential Young Investigator Award (to G. L. V.), and National Institutes of Health Grant R01-AI29179 (to G. J. N.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.