Evolution and expansion of the Mycobacterium tuberculosis PE and PPE multigene families and their association with the duplication of the ESAT-6 (esx) gene cluster regions

Table 2 Paired genes present in both the PE and PPE multigene families.*

Sub-Lineage**	Paired genes		Associated ESAT-6 (*esx) gene cluster region**
	(PE)	(PPE)
I	Rv3872	Rv3873	Situated in ESAT-6 (esx) gene cluster region 1
II	Rv0285	Rv0286	Situated in ESAT-6 (esx) gene cluster region 3
II	Rv3018A	Rv3018c	Duplicated from ESAT-6 (esx) gene cluster region 3
II	Rv3022A	Rv3021/22c	Duplicated from ESAT-6 (esx) gene cluster region 3
II	Rv1386	Rv1387	Associated with ESAT-6 (esx) gene cluster region 3
III	Rv3893c	Rv3892c	Situated in ESAT-6 (esx) gene cluster region 2
III	Rv2107	Rv2108	Associated with ESAT-6 (esx) gene cluster region 2
III or IV	Rv2431c	Rv2430c	Associated with ESAT-6 (esx) gene cluster region 2 or 5
IV	Rv1788/91	Rv1787/89/90	Situated in ESAT-6 (esx) gene cluster region 5
IV	Rv3622c	Rv3621c	Duplicated from ESAT-6 (esx) gene cluster region 5
IV	Rv1195	Rv1196	Duplicated from ESAT-6 (esx) gene cluster region 5
IV	Rv1040c	Rv1039c	Duplicated from ESAT-6 (esx) gene cluster region 5
IV	Rv1169c	Rv1168c	Associated with ESAT-6 (esx) gene cluster region 5
IV	Rv1806	Rv1801/2/7/8/9	Associated with ESAT-6 (esx) gene cluster region 5
IV	Rv3477	Rv3478	Associated with ESAT-6 (esx) gene cluster region 5
IV	Rv2769c	Rv2768c/70c	Associated with ESAT-6 (esx) gene cluster region 5
IV	Rv0916c	Rv0915c	Associated with ESAT-6 (esx) gene cluster region 5

* Although they are physically-separated, Rv3746c and Rv3739c seems to have been a pair associated with either ESAT-6 gene cluster region 1 or 3, which was disrupted by the insertion of a number of genes.
** See Figure 5 and 6 for definition of sublineages.
*** "Situated in" denotes genes situated within ESAT-6 (esx) gene cluster regions, "Duplicated from" denotes genes confirmed to be duplicated from ESAT-6 (esx) gene clusters due to the presence of ESAT-6 and CFP-10 genes immediately adjacent to them, "Associated with" denotes genes which are hypothesized to have been duplicated from ESAT-6 (esx) gene cluster regions, as they are very homologous to their paralogues within the clusters (see Figure 1).

ISSN: 2730-7182