TY - JOUR
T1 - Bacteriophage P22 tail accessory factor GP26 is a long triple-stranded coiled-coil
AU - Andrews, Dewan
AU - Butler, James S.
AU - Al-Bassam, Jawdat
AU - Joss, Lisa
AU - Winn-Stapley, Danella A.
AU - Casjens, Sherwood
AU - Cingolani, Gino
PY - 2005/2/18
Y1 - 2005/2/18
N2 - P22 is a well characterized tailed bacteriophage that infects Salmonella enterica serovar Typhimurium. It is characterized by a "short" tail, which is formed by five proteins: the dodecameric portal protein (gp1), three tail accessory factors (gp4, gp10, gp26), and six trimeric copies of the tail-spike protein (gp9). We have isolated the gene encoding tail accessory factor gp26, which is responsible for stabilization of viral DNA within the mature phage, and using a variety of biochemical and biophysical techniques we show that gp26 is very likely a triple stranded coiled-coil protein. Electron microscopic examination of purified gp26 indicates that the protein adopts a rod-like structure ∼210 Å in length. This trimeric rod displays an exceedingly high intrinsic thermostability (Tm ∼85°C), which suggests a potentially important structural role within the phage tail apparatus. We propose that gp26 forms the thin needle-like fiber emanating from the base of the P22 neck that has been observed by electron microscopy of negatively stained P22 virions. By analogy with viral trimeric coiled-coil class I membrane fusion proteins, gp26 may represent the membrane-penetrating device used by the phage to pierce the host outer membrane.
AB - P22 is a well characterized tailed bacteriophage that infects Salmonella enterica serovar Typhimurium. It is characterized by a "short" tail, which is formed by five proteins: the dodecameric portal protein (gp1), three tail accessory factors (gp4, gp10, gp26), and six trimeric copies of the tail-spike protein (gp9). We have isolated the gene encoding tail accessory factor gp26, which is responsible for stabilization of viral DNA within the mature phage, and using a variety of biochemical and biophysical techniques we show that gp26 is very likely a triple stranded coiled-coil protein. Electron microscopic examination of purified gp26 indicates that the protein adopts a rod-like structure ∼210 Å in length. This trimeric rod displays an exceedingly high intrinsic thermostability (Tm ∼85°C), which suggests a potentially important structural role within the phage tail apparatus. We propose that gp26 forms the thin needle-like fiber emanating from the base of the P22 neck that has been observed by electron microscopy of negatively stained P22 virions. By analogy with viral trimeric coiled-coil class I membrane fusion proteins, gp26 may represent the membrane-penetrating device used by the phage to pierce the host outer membrane.
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U2 - 10.1074/jbc.C400513200
DO - 10.1074/jbc.C400513200
M3 - Article
C2 - 15591072
AN - SCOPUS:14044262392
VL - 280
SP - 5929
EP - 5933
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 7
ER -