IS Elements in pNRC100
| Element | Homolog(s)[i] | Size (kb) | Copy no. | Comments |
| ISH2 | — | 0.5 | 4 | lacks ORF |
| ISH3 | ISH27, ISH51 | 1.4 | 8 | heterogeneous |
| ISH4 | ISH50 | 1.0 | 1 | |
| ISH5 | — | 1.5 | 2 | interrupted by ISH11 |
| ISH7 | ISH24 | 2.9/3.3 | 2 | heterogeneous |
| ISH8 | ISH26 | 1.4 | 6 | heterogeneous |
| ISH9 | ISH28 | 0.9 | 2 | |
| ISH11 | — | 1.1 | 2 |
[i] Homologs are similar but nonidentical IS elements reported previously in other halophiles (Charlebois and Doolittle 1989;DasSarma 1993). ISH51 was reported from Haloferax volcanii,and the other ISH elements listed were fromHalobacterium strains.