PMID:22234860

Citation	Ang, D and Georgopoulos, C (2012) An ORFan no more: the bacteriophage T4 39.2 gene product, NwgI, modulates GroEL chaperone function. Genetics 190:989-1000
Abstract	Bacteriophages are the most abundant biological entities in our biosphere, characterized by their hyperplasticity, mosaic composition, and the many unknown functions (ORFans) encoded by their immense genetic repertoire. These genes are potentially maintained by the bacteriophage to allow efficient propagation on hosts encountered in nature. To test this hypothesis, we devised a selection to identify bacteriophage-encoded gene(s) that modulate the host Escherichia coli GroEL/GroES chaperone machine, which is essential for the folding of certain host and bacteriophage proteins. As a result, we identified the bacteriophage RB69 gene 39.2, of previously unknown function and showed that homologs of 39.2 in bacteriophages T4, RB43, and RB49 similarly modulate GroEL/GroES. Production of wild-type bacteriophage T4 Gp39.2, a 58-amino-acid protein, (a) enables diverse bacteriophages to plaque on the otherwise nonpermissive groES or groEL mutant hosts in an allele-specific manner, (b) suppresses the temperature-sensitive phenotype of both groES and groEL mutants, (c) suppresses the defective UV-induced PolV function (UmuCD) of the groEL44 mutant, and (d) is lethal to the host when overproduced. Finally, as proof of principle that Gp39.2 is essential for bacteriophage growth on certain bacterial hosts, we constructed a T4 39.2 deletion strain and showed that, unlike the isogenic wild-type parent, it is incapable of propagating on certain groEL mutant hosts. We propose a model of how Gp39.2 modulates GroES/GroEL function.
Links	PubMed PMC3296260 Online version:10.1534/genetics.111.135640
Keywords	Amino Acid Sequence; Bacterial Proteins/metabolism; Bacteriophage T4/genetics; Bacteriophage T4/metabolism; Chaperonin 60/genetics; Chaperonin 60/metabolism; DNA-Directed DNA Polymerase/chemistry; Escherichia coli/metabolism; Escherichia coli/virology; Escherichia coli Proteins/chemistry; Gene Expression; Gene Order; Molecular Sequence Data; Mutation; Plasmids/genetics; Protein Folding; Temperature; Viral Proteins/genetics; Viral Proteins/metabolism
edit table

Annotations

Gene product	Qualifier	GO Term	Evidence Code	with/from	Aspect	Extension	Notes	Status
BPT4:D9IE38		GO:1903332: regulation of protein folding	ECO:0001165: colony counting evidence used in manual assertion		P		Gp39.2, which is a bacteriophage T4 protein, is believed to modulate the host's (E. coli) GroEL/GroES chaperone machine, which aids in the correct folding of both host and bacteriophage proteins. Gp39.2 is thought to play a part in correctly folding the E. coli host protein UmuC, which is part of the DNA Polymerase V complex. The authors believe that the GroEL/GroES complex is required for the DNA PolV to work and proofread in the bacteria cell. This relationship between Gp39.2 and DNA PolV is illustrated in Figure 5 where an E. coli mutant (that was only a mutant for isolation purposes for plating) was plated with and without the plasmid containing Gp39.2. The bacterium were then exposed to UV irradiation and were grown with and without arabinose, which showed which mutant bacteria had Gp39.2 in them. The Gp39.2 mutant bacteria were much more frequently seen while plating as opposed to the non-Gp39.2 mutant bacteria.	complete CACAO 13727

References

See Help:References for how to manage references in GONUTS.