Actinomycetes are the most significant source of microbial natural products ever discovered, accounting for more than one half of all known antibiotics. JGI's collaborators have recently discovered a new actinomycete genus, for which they have proposed the name Salinispora, and this taxon is proving to be an important source of novel secondary metabolites, including a new treatment for cancer. These actinomycetes reside in marine sediments and display fundamental physiological differences from those that occur on land, including an obligate requirement of seawater for growth. This will be a small genome program for draft shotgun sequencing of the type strains of the two currently recognized species in this genus, S. tropicalis and S. arenicola. These will be the first marine actinomycetes, and more generally, the first marine Gram-positive bacteria, to be sequenced, thus providing important new information about an environmentally significant yet poorly studied group of prokaryotes. They will also be the only actinomycetes in the family Micromonosporaceae, as well as the only secondary-metabolite-producing actinomycetes other than two Streptomyces species to be sequenced, providing useful opportunities for comparative analyses. The genome sequences will advance our understanding of how secondary metabolites are produced and provide new information about the evolutionary significance of secondary metabolite production, how bacteria adapt to life in the ocean, and the ecological roles of actinomycetes in marine sediments.