An hsp70 homolog is encoded on the plastid genome of the red alga,Porphyra umbilicalis

Abstract
A PCR experiment using Porphyra umbilicalis DNA as the template and degenerate oligonucleotides representing conserved regions of hsp70 amino acid sequences generated a 1 kb product that hybridized exclusively to the plastid DNA of this red alga. DNA sequencing of two continguous EcoRI plastid DNA clones revealed a 620 amino acid open reading frame with 71% identity to the dnaK gene of the cyanobacterium. Synechocystis 6803. Northern hybridization experiments detected a 2.3 kb transcript that is present in control (15°C) cultures and increases approximately 7-fold upon heat shock (75 minutes at 30°C).