Structure Report for: 3HC7

Payne, K., Sun, Q., Sacchettini, J., Hatfull, G.F.

Title: Mycobacteriophage Lysin B is a novel mycolylarabinogalactan esterase
Payne K, Sun Q, Sacchettini J, Hatfull GF
Ref: Molecular Microbiology, 73:367, 2009 : PubMed
Abstract


ESTHER: Payne_2009_Mol.Microbiol_73_367
PubMedSearch: Payne 2009 Mol.Microbiol 73 367
PubMedID: 19555454
Gene_locus related to this paper: bpmd2-vg12

Abstract

Mycobacteriophages encounter a unique problem among phages of Gram-positive bacteria, in that lysis must not only degrade the peptidoglycan layer but also circumvent a mycolic acid-rich outer membrane covalently attached to the arabinogalactan-peptidoglycan complex. Mycobacteriophages accomplish this by producing two lysis enzymes, Lysin A (LysA) that hydrolyses peptidoglycan, and Lysin B (LysB), a novel mycolylarabinogalactan esterase, that cleaves the mycolylarabinogalactan bond to release free mycolic acids. The D29 LysB structure shows an alpha/beta hydrolase organization with a catalytic triad common to cutinases, but which contains an additional four-helix domain implicated in the binding of lipid substrates. Whereas LysA is essential for mycobacterial lysis, a Giles DeltalysB mutant mycobacteriophage is viable, but defective in the normal timing, progression and completion of host cell lysis. We propose that LysB facilitates lysis by compromising the integrity of the mycobacterial outer membrane linkage to the arabinogalactan-peptidoglycan layer.



        

Title: Genome structure of mycobacteriophage D29: implications for phage evolution
Ford ME, Sarkis GJ, Belanger AE, Hendrix RW, Hatfull GF
Ref: Journal of Molecular Biology, 279:143, 1998 : PubMed
Abstract


ESTHER: Ford_1998_J.Mol.Biol_279_143
PubMedSearch: Ford 1998 J.Mol.Biol 279 143
PubMedID: 9636706
Gene_locus related to this paper: bpmd2-vg12, bpmdd-prxh

Abstract

Mycobacteriophage D29 is a lytic phage that infects both fast and slow-growing mycobacterial species. The complete genome sequence of D29 reveals that it is a close relative of the temperate mycobacteriophage L5, whose sequence has been described previously. The overall organization of the D29 genome is similar to that of L5, although a 3.6 kb deletion removing the repressor gene accounts for the inability of D29 to form lysogens. Comparison of the two genomes shows that they are punctuated by a large number of insertions, deletions, and substitutions of genes, consistent with the genetic mosaicism of lambdoid phages.