9.B.2 The Integral Membrane CAAX Protease-2 (CAAX Protease2) Family
The CAAX Protease2 family includes members that are similar in many ways to the CAAX protease family (9.B.1), but the sequence divergence is extensive. The latter proteins do not bring up members of the former family in PSI-BLAST searches, and vise versa. These proteins bring up 3.A.1.115.2 (NatB, the membrane constituent of the Na exporting ABC system, NatAB) and 3.A.1.110.1 (MceF, with 7 TMSs that may be a CAAX protease and not part of the transporter). These proteins may have a 2 + 2 + 2 TMS topology. Sortases (TC# 9.B.297) are distantly related to members of the CAAX protease-2.1 subfamily, and some of these are listed under TC subfamily 9.B.2.14 (Haft 2024).
This family belongs to the: CAAX Superfamily.
References associated with 9.B.2 family:
Biswas, S. and I. Biswas. (2014). A conserved streptococcal membrane protein, LsrS, exhibits a receptor-like function for lantibiotics. J. Bacteriol. 196: 1578-1587. 24509319
Grell, T.A.J., W.M. Kincannon, N.A. Bruender, E.J. Blaesi, C. Krebs, V. Bandarian, and C.L. Drennan. (2018). Structural and spectroscopic analyses of the sporulation killing factor biosynthetic enzyme SkfB, a bacterial AdoMet radical sactisynthase. J. Biol. Chem. 293: 17349-17361. 30217813
Haft, D.H. (2024). discovery of the myxosortases that process MYXO-CTERM and three novel prokaryotic C-terminal protein-sorting signals that share invariant Cys residues. J. Bacteriol. 206: e0017323. 38084967
Pei, J. and N.V. Grishin. (2001). Type II CAAX prenyl endopeptidases belong to a novel superfamily of putative membrane-bound metalloproteases. Trends. Biochem. Sci. 26: 275-277. 11343912