"M. genitalium" has 525 genes. There are 482 protein-encoding genes in a circular chromosome of 582,970 base pairs. An initial study of the "M. genitalium" genome with shotgun sequencing was done by Peterson in 1993. It was then sequenced by Fraser and others. It was found to contain only 470 predicted coding regions, including genes required for DNA replication, transcription and translation, DNA repair, cellular transport, and energy metabolism. It was the second complete bacterial genome ever sequenced, after "Haemophilus influenzae".