1.E.7 The HP1 Holin (HP1 Holin) Family See 1.E for a generalized description of Holins. The NucE protein in Serratia marcescens shows homology to phage holin proteins involved in releasing lysozyme to the peptidoglycan of Gram-negative bacteria. The protein contains two characteristic TMSs with a positively charged C-terminus. When the nucC operon carrying the nucEDC genes is placed in the Escherichia coli chromosome, NucE functions as a holin. Additionally, NucE can complement lysis-defective bacteriophage mutants to allow for plaque formation and release of phage. Although NucE can function as a holin it is not involved in the transport of nuclease, an extracellular protein encoded by the nucA gene.
This family belongs to the: Holin II Superfamily .
References associated with 1.E.7 family:
Berkmen, M., M.J. Benedik, and U. Bläsi. (1997). The Serratia marcescens NucE protein functions as a holin in Escherichia coli. J. Bacteriol. 179: 6522-6524. 9335307
Jin, S., Y. Chen, G.E. Christie and M.J. Benedik (1996). Regulation of the Serratia marcescens extracellular nuclease: positive control by a homolog of P2 Ogr encoded by a cryptic prophage. J. Mol. Biol. 256: 264-278. 8594195
Strych U., W. Dai, and M.J. Benedik (1999). The NucE and NucD lysis proteins are not essential for secretion of the Serratia marcescens extracellular nuclease. Microbiology 145: 1209-1216. 10376837