The genome anal- yses provide few insights into why it is a good host, especially since it appears to carry a type 1 restriction-modification sys- tem (SiH1435 to SiH1437).
The CRISPR/Cas and CRISPR/Cmr modules of strain HVE10/4 are relatively com- plex, as they also are for strain REY15A and other Sulfolobus strains.