RESUMEN
The 4/1 protein of unknown function is encoded by a single-copy gene in most higher plants. The 4/1 protein of Nicotiana tabacum (Nt-4/1 protein) has been shown to be alpha-helical and predominantly expressed in conductive tissues. Here, we report the analysis of 4/1 genes and the encoded proteins of lower land plants. Sequences of a number of 4/1 genes from liverworts, lycophytes, ferns and gymnosperms were determined and analyzed together with sequences available in databases. Most of the vascular plants were found to encode Magnoliophyta-like 4/1 proteins exhibiting previously described gene structure and protein properties. Identification of the 4/1-like proteins in hornworts, liverworts and charophyte algae (sister lineage to all land plants) but not in mosses suggests that 4/1 proteins are likely important for plant development but not required for a primary metabolic function of plant cell.
Asunto(s)
Evolución Molecular , Genes de Plantas , Modelos Genéticos , Proteínas de Plantas/genética , Viridiplantae/genética , Secuencia de Aminoácidos , Secuencia de Bases , Briófitas/genética , Briófitas/metabolismo , Carofíceas/genética , Carofíceas/metabolismo , Biología Computacional , Secuencia Conservada , Cycadopsida/genética , Cycadopsida/metabolismo , Bases de Datos Genéticas , Biblioteca Genómica , Magnoliopsida/genética , Magnoliopsida/metabolismo , Datos de Secuencia Molecular , Filogenia , Desarrollo de la Planta , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Conformación Proteica , Alineación de Secuencia , Viridiplantae/metabolismoRESUMEN
The 16S-23S rRNA internal transcribed spacer regions (ITS1) from 14 strains of Pseudomonas syringae and P. fluorescens were sequenced. ITS1 exhibited significant sequence variability among different operons within a single genome. From 1 to 4 types of ITS1 were found in individual genomes of the P. syringae and P. fluorescens strains. A total of eight ITS1 types were identified among strains studied. The ITS1 nucleotide sequences consisted of conserved blocks including, among others, a stem-forming region of box B, tRNAIle and tRNAAla genes and several variable blocks. The differences in the variable regions were mostly due to insertions and/or deletions of nucleotide blocks. The intragenomic heterogeneity of ITS1 was brought about by different combinations of variable blocks, which possibly have resulted from recombination and horizontal transfer.