|Schauser et al. (2005):
|Genetic studies in Lotus japonicus and pea have identified Nin as a core symbiotic gene required for establishing symbiosis between legumes and nitrogen fixing bacteria collectively called Rhizobium. Sequencing of additional Lotus cDNAs combined with analysis of genome sequences from Arabidopsis and rice reveals that Nin homologues in all three species constitute small gene families. In total, the Arabidopsis and rice genomes encode nine and three NIN-like proteins (NLPs), respectively. We present here a bioinformatics analysis and prediction of NLP evolution. On a genome scale we show that in Arabidopsis, this family has evolved through segmental duplication rather than through tandem amplification. Alignment of all predicted NLP protein sequences shows a composition with six conserved modules. In addition, Lotus and pea NLPs contain segments that might characterize NIN proteins of legumes and be of importance for their function in symbiosis. The most conserved region in NLPs, the RWP-RK domain, has secondary structure predictions consistent with DNA binding properties. This motif is shared by several other small proteins in both Arabidopsis and rice. In rice, the RWP-RK domain sequences have diversified significantly more than in Arabidopsis. Database searches reveal that, apart from its presence in Arabidopsis and rice, the motif is also found in the algae Chlamydomonas and in the slime mold Dictyostelium discoideum. Thus, the origin of this putative DNA binding region seems to predate the fungus-plant divide.
|Schauser, L; Roussis, A; Stiller, J; Stougaard, J. 1999. A plant regulator controlling development of symbiotic root nodules. Nature 402(6758):191-5 PubMed
|Number of species containing the TAP:
|Number of available proteins:
The colour code corresponds to the rules for the domains:
should not be contained
(Domain names are clickable)
Phylogenetic tree for Archeaplastida:
No tree was calculated yet.
The following table shows the distribution of RWP-RK 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.