Home

TOBFAC: The database of tobacco transcription factors

Family: Alfin

Minimum number of tobacco Alfin genes: 9

Count of tobacco Alfin sequences: 24

Pfam accession: Alfin-like

SHOULD possess Alfin-like domain and COULD   possess PHD SNF2_N zf-C2H2 zf-C5HC2 zf-CCCH zf-TAZ domains but SHOULD NOT possess DDT Homeobox JmjC JmjN domains

Alfin1 cDNA, obtained by differential screening of a poly(A)+ library from salt-tolerant alfalfa cells, encodes a novel protein with a Cys4 and His/Cys3 putative zinc-binding domain that suggests a possible role for this protein in transcriptional regulation. We have expressed the cDNA in Escherichia coli and show that the recombinant Alfin1 protein binds DNA in a sequence-specific manner. The DNA recognition sequence was determined from individual clones isolated after four rounds of random oligonucleotide selection in gel retardation assays, coupled with PCR amplification of the selected sequences. The consensus binding site for Alfin1 is shown to contain two to five G-rich triplets with the conserved core of GNGGTG or GTGGNG in clones showing high-efficiency binding. DNA binding of the recombinant Alfin1 was inhibited by EDTA. Alfin1 mRNA was found predominantly in alfalfa roots. Growth of salt-sensitive Medicago sativa L on 171 mM NaCl led to a slight decrease in Alfin1 mRNA, while the salt-tolerant plants showed no decrease in Alfin1 mRNA levels. Interestingly, recombinant Alfin1 binds efficiently to three fragments of the MsPRP2 promoter, each containing consensus sequences identified by the random oligonucleotide selection. Since MsPRP2 transcripts were shown to be root-specific and accumulated in alfalfa roots in a salt-inducible manner, Alfin1 may play a role in the regulated expression of MsPRP2 in alfalfa roots and contribute to salt tolerance in these plants .

The Cys-rich sequence Cys-X₂-Cys-X₁₁-Cys-Cys-X₂-Cys-X₄-His-X₂-Cys-X₉-His-X₅-Cys-X₂-Cys- encoded by Alfin-1 contains one putative Cys₄ zinc finger structure and another His/Cys₃ structure, thus making it a good candidate for a new category of zinc finger nucleic adid-binding protein in plants .

Papers

Bastola, DR; Pethe, VV; Winicov, I. Alfin1, a novel zinc-finger protein in alfalfa roots that binds to promoter elements in the salt-inducible MsPRP2 gene. Plant Mol. Biol. 1998. 38(6):1123-35 PMID: 9869418

Winicov I. cDNA encoding putative zinc finger motifs from salt-tolerant alfalfa (Medicago sativa L.) cells. Plant Physiol. 1993 June; 102 (2): 681¨C682 PMID: 8108516

Number of contigs: 33

Number of singlets: 0

N terminus (up to 50th amino acid) – 9

50 aa – 110 aa – 7

120 aa – 185 – 3

C terminus including finger – 5

Total minimum number – 9

Search sequences and info

Transcription factor sequences

Tobacco published genes related to transcription factor family Alfin

Authors of this site:

Paul J Rushton
Marta T. Bokowiec
Xianfeng (Jeff) Chen
Thomas (Tom) W Laudeman
Jennifer F. Brannock
Michael P. Timko

Contact:

pr8y@virginia.edu