Protein Family Models

These proteins are predicted transmembrane proteins with probably four transmembrane spans. The 1.E.40 is represented by the mycobacterial 4 phage holin, but it also contains many cyanobacterial. proteobacterial and firmicute proteins. Holins are encoded within the genomes of Gram-positive and Gram-negative bacteria as well as in those of the bacteriophage of these organisms. The primary function of holins appears to be transport of murein hydrolases across the cytoplasmic membrane to the cell wall where these enzymes hydrolyse the cell wall polymer as a prelude to cell lysis. When chromosomally encoded the enzymes are therefore autolysins. Holins may also facilitate leakage of electrolytes and nutrients from the cell cytoplasm, thereby promoting cell death. Some may catalyse export of nucleases. [1]. 23043507. Diversity in bacterial lysis systems: bacteriophages show the way. Catalao MJ, Gil F, Moniz-Pereira J, Sao-Jose C, Pimentel M;. FEMS Microbiol Rev. 2012; [Epub ahead of print] (from Pfam)

Date:

2024-10-16

This family consists of phosphodiesterases, including human plasma-cell membrane glycoprotein PC-1 / alkaline phosphodiesterase i / nucleotide pyrophosphatase (nppase). These enzymes catalyse the cleavage of phosphodiester and phosphosulfate bonds in NAD, deoxynucleotides and nucleotide sugars [1]. Also in this family is ATX an autotaxin, tumour cell motility-stimulating protein which exhibits type I phosphodiesterases activity [4]. The alignment encompasses the active site [3,4]. Also present with in this family is 60-kDa Ca2+-ATPase form F. odoratum [2]. [1]. 9344668. Molecular cloning and chromosomal localization of PD-Ibeta (PDNP3), a new member of the human phosphodiesterase I genes. Jin-Hua P, Goding JW, Nakamura H, Sano K;. Genomics 1997;45:412-415. [2]. 8617788. Cloning and expression of the unique Ca2+-ATPase from Flavobacterium odoratum. Peiffer WE, Desrosiers MG, Menick DR;. J Biol Chem 1996;271:5095-5100. [3]. 7730366. Affinity purification and cDNA cloning of rat neural differentiation and tumor cell surface antigen gp130RB13-6 reveals relationship to human and murine PC-1. Deissler H, Lottspeich F, Rajewsky MF;. J Biol Chem 1995;270:9849-9855. [4]. 7982964. cDNA cloning of the human tumor motility-stimulating protein, autotaxin, reveals a homology with phosphodiesterases. Murata J, Lee HY, Clair T, Krutzsch HC, Arestad AA, Sobel ME, Liotta LA, Stracke ML;. J Biol Chem 1994;269:30479-30484. (from Pfam)

Date:

2024-10-16