Husbands et al. (2007): Conserved in a variety of evolutionarily divergent plant species, LOB DOMAIN (LBD) genes define a large, plant-specific family of largely unknown function. LBD genes have been implicated in a variety of developmental processes in plants, although to date, relatively few members have been assigned functions. LBD proteins have previously been predicted to be transcription factors, however supporting evidence has only been circumstantial. To address the biochemical function of LBD proteins, we identified a 6-bp consensus motif recognized by a wide cross-section of LBD proteins, and showed that LATERAL ORGAN BOUNDARIES (LOB), the founding member of the family, is a transcriptional activator in yeast. Thus, the LBD genes encode a novel class of DNA-binding transcription factors. Post-translational regulation of transcription factors is often crucial for control of gene expression. In our study, we demonstrate that members of the basic helix-loop-helix (bHLH) family of transcription factors are capable of interacting with LOB. The expression patterns of bHLH048 and LOB overlap at lateral organ boundaries. Interestingly, the interaction of bHLH048 with LOB results in reduced affinity of LOB for the consensus DNA motif. Thus, our studies suggest that bHLH048 post-translationally regulates the function of LOB at lateral organ boundaries.


1) Husbands, A; Bell, EM; Shuai, B; Smith, HM; Springer, PS. 2007. LATERAL ORGAN BOUNDARIES defines a new family of DNA-binding transcription factors and can interact with specific bHLH proteins. Nucleic Acids Res. 35(19):6663-71 PubMed
2) Lang, D; Weiche, B; Timmerhaus, G; Richardt, S; Riano-Pachon, DM; Correa, LG; Reski, R; Mueller-Roeber, B; Rensing, SA. 2010. Genome-wide phylogenetic comparative analysis of plant transcriptional regulation: a timeline of loss, gain, expansion, and correlation with complexity. Genome Biol Evol. 2: 488-503 PubMed


Name: AS2/LOB
Class: TF
Number of species containing the TAP: 98
Number of available proteins: 4182

The colour code corresponds to the rules for the domains:

should be contained
should not be contained

Domain rules:

(Domain names are clickable)

Phylogenetic tree for Archeaplastida:

To view the tree click here.

TAP distribution:

The following table shows the distribution of AS2/LOB over all species included in TAPscan. The values for e.g. a specific kingdom are shown in the tree below if you expand the tree for that kingdom.

Minimum Maximum Average Median Standard deviation

List of species containing AS2/LOB sorted by kingdomcladesupergrouporderfamily:

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expand kingdom Archaeplastida (4250 proteins in 98 species)