1.B.163. The Cell Wall (Outer Membrane) Porin-2 (PorA2) Family
This family (DUF3068; pfam11271) includes members of about 375 aas with two very hydrophobic TMSs at the N- and C-termini. The PorA of Corynebacterium amycolatum forms water-filled channels that favor the permeation of cations (Dörner et al. 2009, Soltan Mohammadi et al. 2013). The cell-wall channel is wide and water-filled and has a narrow selectivity for cations (Dörner et al. 2009).
Mycolic acid outer membrane porin, PorA(2) of 374 aas and 2 hydrophobic peaks at its N- and C-termini. The protein forms pores that are slightly cation-selective.
PorA of Corynebacterium amycolatum
DUF3068 PorA porin of 364 aas and two TMSs, N- and C-terminal.
PorA of Corynebacterium diphtheriae
DUF3068 domain-containing protein, PorA, of 331 aas and 2 N- and C-terminal TMSs.
PorA(2) of Streptomyces inusitatus
PorA of 340 aas and 2 TMSs.
PorA of Actinoallomurus bryophytorum
DUF3068 domain-containing protein, PorA(2) of 359 aas with 2 TMSs.
PorA(2) of Nocardiopsis potens
Porin PorA family protein of 363 aas and 2 TMSs.
PorA of Catenulispora pinistramenti
DUF3068 domain-containing protein of 321 aas and 2 TM
DUF3068 domain protein of Nonomuraea glycinis
PorA of 391 aas and 2 TMSs, N- and C-terminal (Piselli et al. 2022).
PorA of Rhodococcus ruber
PgfA (MSMEG_0317), a periplasmic protein, interacts with trehalose monomycolate (TMM) and MmpL3 (TC# 2.A.6.5.6). It is a key determinant of polar growth and cell envelope composition in mycobacteria, and the LamA-mediated recruitment of this protein to one side of the cell is a required step in the establishment of cellular asymmetry (Gupta et al. 2022).
PgfA of Mycolicibacterium smegmatis (Mycobacterium smegmatis; mycobacterium phlei)