Taxonomic distribution of proteins containing MBT domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing MBT domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

Cloning of a novel murine gene Sfmbt, Scm-related gene containing four mbt domains, structurally belonging to the Polycomb group of genes.

Usui H, Ichikawa T, Kobayashi K, Kumanishi T
Gene. 2000; 248: 127-35

A novel cDNA clone encoding a protein structurally related to the transcriptional repressor Polycomb group (PcG) proteins, which regulate homeotic genes and others, was isolated from mouse and rat brain. The coding protein contained the SPM domain and mbt repeats, both of which are characteristic of the PcG proteins, and showed significant similarity in amino acid sequence to the Drosophila Sex comb on midleg (Scm) protein. Since this novel protein contains the mbt repeats in four tandem copies, we designated this murine gene as Sfmbt for Scm-related gene containing four mbt domains. Cloning and characterization of the mouse Sfmbt gene revealed that the coding sequence comprised 20 exons, dispersed along approximately 40kb, and mapped to the proximal part of Chromosome 14. Northern blot analysis showed that the Sfmbt mRNAs were expressed most abundantly in the adult testis, and less intensively in all other tissues examined.

The Drosophila melanogaster tumor suppressor gene lethal(3)malignant brain tumor encodes a proline-rich protein with a novel zinc finger.

Wismar J, Loffler T, Habtemichael N, Vef O, Geissen M, Zirwes R, Altmeyer W, Sass H, Gateff E
Mech Dev. 1995; 53: 141-54

The lethal(3)malignant brain tumor [t(3)mbt] gene causes, when mutated, malignant growth of the adult optic neuroblasts and ganglion mother cells in the larval brain and imaginal disc overgrowth. Via overlapping deficiencies a genomic region of approximately 6.0 kb was identified, containing l(3)mbt+ gene sequences. The l(3)mbt+ gene encodes seven transcripts of 5.8 kb, 5.65 kb, 5.35 kb, 5.25 kb, 5.0 kb, 4.4 kb and 1.8 kb. The putative MBT163 protein, encompassing 1477 amino acids, is proline-rich and contains a novel zinc finger. In situ hybridizations of whole mount embryos and larval tissues revealed l(3)mbt+ RNA ubiquitously present in stage 1 embryos and throughout embryonic development in most tissues. In third instar larvae l(3)mbt+ RNA is detected in the adult optic anlagen and the imaginal discs, the tissues directly affected by l(3)mbt mutations, but also in tissues, showing normal development in the mutant, such as the gut, the goblet cells and the hematopoietic organs.