Structural highlights
Function
[MAFG_MOUSE] Since they lack a putative transactivation domain, the small Mafs behave as transcriptional repressors when they dimerize among themselves. However, they seem to serve as transcriptional activators by dimerizing with other (usually larger) basic-zipper proteins and recruiting them to specific DNA-binding sites. Small Maf proteins heterodimerize with Fos and may act as competitive repressors of the NF-E2 transcription factor. Transcription factor, component of erythroid-specific transcription factor NF-E2. Activates globin gene expression when associated with NF-E2. May be involved in signal transduction of extracellular H(+) (By similarity).[1] [2]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Maf transcription factors constitute a family of the basic region-leucine zipper (bZip) factors and recognize unusually long DNA motifs (13 or 14 bp), termed the Maf recognition element (MARE). The MARE harbors extended GC sequences on each side of its core motif, which is similar to TRE or CRE (7 or 8 bp) recognized by the AP1 and CREB/ATF families, respectively. To ascertain the structural basis governing the acquirement of such unique DNA recognition, we determined the crystal structure of the MafG-DNA complex. Each MafG monomer consists of three helices in which the carboxyl-terminal long helix organizes one DNA-contacting element and one coiled-coil dimer formation element. To our surprise, two well-conserved residues, Arg57 and Asn61 in the basic region, play critical roles in Maf-specific DNA recognition. These two residues show unique side-chain orientations and interact directly with the extended GC bases. Maf-specific residues in the amino-terminal and basic regions appear to indirectly stabilize MARE recognition through DNA backbone phosphate interactions. This study revealed an alternative DNA recognition mechanism of the bZip factors that bestows specific target gene profiles upon Maf homodimers or Maf-containing heterodimers.
Structural basis of alternative DNA recognition by Maf transcription factors.,Kurokawa H, Motohashi H, Sueno S, Kimura M, Takagawa H, Kanno Y, Yamamoto M, Tanaka T Mol Cell Biol. 2009 Dec;29(23):6232-44. Epub 2009 Sep 21. PMID:19797082[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Shavit JA, Motohashi H, Onodera K, Akasaka J, Yamamoto M, Engel JD. Impaired megakaryopoiesis and behavioral defects in mafG-null mutant mice. Genes Dev. 1998 Jul 15;12(14):2164-74. PMID:9679061
- ↑ Motohashi H, Katsuoka F, Miyoshi C, Uchimura Y, Saitoh H, Francastel C, Engel JD, Yamamoto M. MafG sumoylation is required for active transcriptional repression. Mol Cell Biol. 2006 Jun;26(12):4652-63. PMID:16738329 doi:http://dx.doi.org/10.1128/MCB.02193-05
- ↑ Kurokawa H, Motohashi H, Sueno S, Kimura M, Takagawa H, Kanno Y, Yamamoto M, Tanaka T. Structural basis of alternative DNA recognition by Maf transcription factors. Mol Cell Biol. 2009 Dec;29(23):6232-44. Epub 2009 Sep 21. PMID:19797082 doi:10.1128/MCB.00708-09
