A novel DNA-binding domain in theShrunken initiator-binding protein (IBP1)
- 1 June 1994
- journal article
- research article
- Published by Springer Nature in Plant Molecular Biology
- Vol. 25 (3) , 493-506
- https://doi.org/10.1007/bf00043877
Abstract
South-western screening of λgt11 expression library with a fragment of theShrunken promoter containing the initiator element resulted in cloning of a novel maize gene. The encoded initiator-binding protein (IBP1) interacts at the transcription start site of theShrunken promoter. Analysis of the 680 amino acid (aa) long polypeptide revealed a novel bipartite DNA-binding domain at the carboxyl terminus. In its amino-terminal part, it is weakly related toMyb R-repeats but the following basic region is also essential for DNA binding. A region of similarity to the conserved 2.1 and 2.2. motifs in bacterial σ-factors is located close to the IBP1 amino terminus. Two putative nuclear localization signals are compatible with the presence of antigenically related polypeptides in nuclear protein extracts. TheIBP1 gene was mapped to the long arm of chromosome 9 (9L095); a second highly related geneIBP2 is located on the short arm of chromosome 1 (1S014). Both genes encode proteins sharing 93% similarity and are transcribed with similar activity in different plant organs. A small 82 nucleotide intron in theIBP2 transcript is found unspliced to a variable degree in different tissues. Translation of this incompletely processed transcript would result in a truncated amino-terminal polypeptide lacking the DNA-binding domain.Keywords
This publication has 49 references indexed in Scilit:
- The p250 subunit of native TATA box-binding factor TFIID is the cell-cycle regulatory protein CCG1Nature, 1993
- Nuclear Targeting of the Maize R Protein Requires Two Nuclear Localization SequencesPlant Physiology, 1993
- Nuclear Targeting in PlantsPlant Physiology, 1992
- The VirD2 protein of A. tumefaciens contains a C-terminal bipartite nuclear localization signal: Implications for nuclear uptake of DNA in plant cellsCell, 1992
- Cooperative interaction of an initiator-binding transcription initiation factor and the helix–loop–helix activator USFNature, 1991
- Two regulatory genes of the maize anthocyanin pathway are homologous: isolation of B utilizing R genomic sequences.Plant Cell, 1989
- The “initiator” as a transcription control elementCell, 1989
- Single-step purification of polypeptides expressed in Escherichia coli as fusions with glutathione S-transferaseGene, 1988
- Molecular cloning of an enhancer binding protein:Isolation by screening of an expression library with a recognition site DNACell, 1988
- Duplicate Genes in MaizeThe American Naturalist, 1951