title: Identification and analysis of the u6 small nuclear RNA gene from Entamoeba histolytica.
abstract: Among the small nuclear RNAs (snRNAs) involved in the spliceosomal processing of pre-mRNA, U6 is the most conserved. As a first evidence for the presence of the splicing machinery in the amitochondrial protozoan Entamoeba histolytica (Eh), we have cloned the u6 snRNA gene. We find that in this organism u6 is a single copy gene that is transcribed as a poly(A)- RNA molecule of approximately 105 nucleotides. We have mapped the 5' end of the U6 snRNA transcript, and identified typical elements of a putative polymerase III promoter. This is the first snRNA gene reported in Eh. Sequence analysis indicates that this gene contains all the conserved nucleotides known to be important for U6 snRNA function. These results, in conjunction with the earlier finding of genes that contain pre-mRNA introns, suggest that Eh has a functional spliceosomal complex.
authors.affiliation: Department of Molecular Recognition and Structural Biology, Instituto de Biotecnología-UNAM, Cuernavaca, Mor., Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Miranda
authors.forename: L M
authors.initials: LM
authors.lastname: Salgado
authors.forename: R
authors.initials: R
authors.lastname: Sánchez-López
authors.forename: A
authors.initials: A
authors.lastname: Alagón
authors.forename: P M
authors.initials: PM
authors.lastname: Lizardi
mesh_terms: D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D016054:DNA, Protozoan; D004748:Entamoeba histolytica / Q000145:classification / Q000235:genetics*; D018628:Gene Dosage; D015870:Gene Expression; D017125:Genes, Protozoan; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D016053:RNA, Protozoan / Q000235:genetics*; D012342:RNA, Small Nuclear / Q000145:classification / Q000235:genetics*; D016415:Sequence Alignment; D017381:Spliceosomes / Q000235:genetics
chemical_list: D016054:DNA, Protozoan; D016053:RNA, Protozoan; D012342:RNA, Small Nuclear