Nucleotide sequence of a second alpha giardin gene and molecular analysis of the alpha giardin genes and transcripts in Giardia lamblia

摘要: Abstract The giardins are a group of proteins with relative molecular masses ( M r s) between 29 000 and 38 that specific to the ventral disk intestinal protozoan parasite Giardia lamblia . We previously have characterized α-giardin, renamed here α-1-giardin, as novel 33-kDa protein located on edges microribbons [5]. Southern blot analysis G. genomic DNA, followed by cloning sequencing, revealed existence related gene we called α-2-giardin. Sequence comparison α-giardin genes reveals 81% identity at nucleotide level 77% predicted amino acid level. α-giardins similar approximately 33 900 very rich in α-helix conformations. Each is present single copy and, like many other known coding sequences, exhibits strong preference for cytidine guanosine third base position each codon. Chromosome hybridization indicates both either same chromosome or chromosomes mobility. Experiments utilizing primer extension RNA sequencing provide evidence transcribed. stable transcripts extremely short leader regions only 3 nucleotides, downstream sequence α-2-giardin AGTPuAA remains consistent element within protein-encoding genes.