Sequence of lamprey vitellogenin. Implications for the lipovitellin crystal structure.

The amino acid sequence of lamprey vitellogenin has been predicted from the nucleotide sequence of cloned cDNA. The sites of proteolytic cleavage that produce the lipovitellin complex from the vitellogenin have been located by comparing the N-terminal sequences of two lamprey lipovitellin polypeptides with the predicted sequence. These results also confirm that the vitellogenin sequence derived here corresponds to the lipovitellin complex for which the crystal structure has been solved previously.

Compartmentalization of mammalian proteins produced in Escherichia coli.

We have examined the patterns of compartmentalization of several mammalian proteins in Escherichia coli which do not have signal peptides or functional signal peptide equivalents. These proteins include (i) human proapolipoprotein A-I (proapoA-I), a 249-residue protein which contains a hexapeptide NH2-terminal prosegment plus a mature domain of 243 residues comprised of tandemly arrayed, docosapeptide repeats with predicted amphipathic alpha-helical structure; (ii) the mature apoA-I molecule without its prosegment; (iii) mouse interleukin-1 beta (IL-1 beta), a 17-kDa protein which is composed of 12 beta strands that form a tetrahedral structure; and (iv) the 31-kDa precursor of IL-1 beta, proIL-1 beta. Efficient expression of these proteins in E.