*1.B.43 The Coxiella* Porin P1 (CPP1) Family** Coxiella burnetii is the etiological agent of Q fever, an obligate intracellular Gram-negative γ-proteobacterium. It lives (1) in the phagolysosome and (2) extracellularly and has a cell cycle involving large cell variants (LCV), small cell variants (SCV) and small dense cells (SDC) (Coleman et al., 2004). The major outer membrane protein (MOMP or P1) is expressed in LCVs, down-regulated in SCV and not at all in SDC (Varghees et al., 2002). The purified detergent-extracted protein has porin activity in planar lipid bilayers (Varghees et al., 2002). It consists largely of β-structure. The reaction catalyzed by porin P1 is: small molecule (out) small molecule (periplasm)
This family belongs to the Outer Membrane Pore-forming Protein I (OMPP-I) Superfamily .
References:
Coleman, S.A., E.R. Fischer, D. Howe, D.J. Mead, and R.A. Heinzen. (2004). Temporal analysis of Coxiella burnetii morphological differentiation. J. Bacteriol. 186: 7344-7352.
Varghees, S., K. Kiss, G. Frans, O. Braha, and J.E. Samuel. (2002). Cloning and porin activity of the major outer membrane protein P1 from Coxiella burnetii. Infect. Immun. 70: 6741-6750.
Examples:
TC#	Name	Organismal Type	Example
1.B.43.1.1	Porin P1	γ-Proteobacteria	*Porin P1 of Coxiella burnetii* (AAM03442)**

1.B.43.1.2	Putative porin	γ-Proteobacteria	Putative porin of Legionella longbeachae

1.B.43.1.3	Putative porin	β-Proteobacteria	Putative porin of Polynucleobacter necessarius

Examples:
TC#	Name	Organismal Type	Example