GIB (Genome Information Broker) provides an integrated search of Bacteria, Archaea, Eukaryota complete genome sequences. Because the genome sequence data of Prochlorococcus marinus MED4, Prochlorococcus marinus MIT9313, and Synechococcus sp. WH 8102 were released, we incorporated them to GIB, and now you can search those data.
References (Institutes):
Prochlorococcus marinus MED4 (JGI):
Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche differentiation, Nature [Epub ahead of print] (2003)

Prochlorococcus marinus MIT9313 (JGI):
Genome divergence in two Prochlorococcus ecotypes reflects oceanic niche differentiation, Nature [Epub ahead of print] (2003)

Synechococcus sp. WH 8102 (JGI):
The genome of a motile marine Synechococcus, Nature [Epub ahead of print] (2003)