J Mol Biol 1975, 98:503–517.PubMedCrossRef Competing interests The authors declare that they have no competing interests. Authors’ contributions

CJ designed the study; carried out the CB-839 concentration purification and characterisation of the LES phages and rates of induction and drafted the manuscript. JL carried out initial induction of the phages from the native host. HK and CJ carried out the host range study. AH clone-typed each clinical P. aeruginosa isolate. JC prepared samples for electron microscopy of LESφ2 and LESφ3. MB and CW jointly conceived of the study and participated in its design and coordination and helped to draft the manuscript. All authors read and approved the final manuscript.”
“Background It has been estimated that more than half of all proteins are glycoproteins [1], a proportion expected to be much higher if only secretory proteins are considered. The term secretory will be used in this article as comprising all proteins entering the secretory pathway, i.e. all proteins having a signal peptide. Glycosyl residues, mainly N-acetylgalactosamine, mannose, galactose or glucose, can be linked to proteins via asparagine (N-glycosylation) or via hydroxylated amino acids including AR-13324 mw serine, threonine, and, more rarely, tyrosine, hydroxyproline and hydroxylysine

(O-glycosylation) [2, 3]. The first step of O-glycosylation in fungi generally consists in the addition of 1–3 mannose units from dolichyl phosphate mannose

to Ser/Thr residues in target proteins [3], by the JIB04 in vivo action of protein O-mannosyltransferases (PMTs) in the endoplasmic reticulum. The initial addition of glucose or galactose residues to Ser/Thr has also been reported for Trichoderma[2]. The chain is then extended, as the protein continues the secretion through Golgi, by several other enzymes generating linear or branched sugar chains composed mostly of mannose residues. Yeast usually have linear sugar chains composed exclusively of mannose [4], but filamentous fungi may have branched chains containing also glucose or galactose [2, 3]. The physiological function of O-glycosylation has been established mostly by analyzing null mutants PIK3C2G in one or more PMT genes, which show a reduced ability to add sugars to Ser/Thr residues in the secretion pathway. A role for O-glycosylation could be established in enhancing the stability and solubility of the proteins, in protecting from proteases, as a sorting determinant, and in the development and differentiation of the fungal hyphae [2]. It is common that the knock-out of a particular PMT gene, or the simultaneous deletion of several of them, causes loss of viability or strong defects such as lower conidiation, changes in fungal morphology, etc. [2], emphasizing the importance of O-glycosylation for the biology of fungal organisms.