Plasmodium 'exportome' statistics. (a) Distribution of exon counts in genes with PEXEL export signatures compared with all P. falciparum genes, demonstrating a clear trend towards two exon genes in the P. falciparum exportome. (b) First intron phase for PEXEL exported genes compared with all P. falciparum genes, showing an extremely strong trend towards a phase 0 first intron amongst genes with export signatures. (c) Counts of classic (intron between signal sequence and PEXEL) and non-classic genes in the P. falciparum exportome, stratified by exon count. (d) Distributions of the number of predicted transmembrane domains for exported P. falciparum proteins, Rifins and Stevors, and the P. falciparum proteome as a whole. Rifins and Stevors are, in general, predicted to have two transmembrane domains, and members of the remaining complement of the P. falciparum exportome are slightly less likely to be soluble than P. falciparum proteins in general, and are also less likely to be multi-membrane spanning. (e) Comparison of the P. falciparum exportome with hybrid exportomes of the P. vivax and P. berghei lineages. Numbers of PEXEL exported uniques and families are shown, as well as any previously described families and uniques not apparently exported by PEXEL mediated mechanisms. Web logos constructed from instances of the motif in the three exportomes are also shown. References to gene families from species other than P. falciparum are indicated in brackets.
Sargeant et al. Genome Biology 2006 7:R12 doi:10.1186/gb-2006-7-2-r12