GENOMIC STRUCTURE AND SEQUENCE-ANALYSIS OF DROSOPHILA-MELANOGASTER HSC70 GENES

We report the identification of two new members of the Drosophila mela nogaster HSP70 gene family, HSC3 and HSC5. DNA sequence analysis predi cts that HSC3 encodes a 72-kDa protein with a hydrophobic leader seque nce and a C-terminal retrieval tetrapeptide, KDEL, characteristics ass ociated with luminal endoplasmic reticulum (ER) proteins. Sequence ana lysis predicts that HSC5 encodes a 74-Kda protein with a characteristi c mitochondrial leader sequence. We report the deduced amino acid (aa) sequence for the previously identified gene, HSC1. HSC1 encodes a 70- kDa protein lacking a leader sequence and is presumed to have a cytopl asmic localization. A comparison of the deduced aa sequences of these and hsc70 proteins from different species indicates that hsc70 protein s residing in the same intracellular compartment in different organism s are more similar to each other than are hsc70s from the same organis m, but different organelles.