Gene Ontology annotation through association of InterPro records with GO terms.
Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping
Combined Automated Annotation using Multiple IEA Methods
Bacteriophage lambda PaPa: not the mother of all lambda phages.
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Ur-lambda virions possess thin, jointed side tail fibers encoded by stf (which is frameshifted in laboratory lambda PaPa) and assembled with the help of tfa, conferring expanded receptor specificity and faster adsorption to Escherichia coli.
"The Ur-lambda virions have thin, jointed tail fibers that are absent from lambda wild type. Two novel proteins of Ur-lambda constitute the fibers: the product of stf, the gene that is disrupted in lambda wild type by the frameshift mutation, and the product of gene tfa, a protein that is implicated in facilitating tail fiber assembly. Relative to lambda wild type, Ur-lambda has expanded receptor specificity and adsorbs to Escherichia coli cells more rapidly."
The role of side tail fibers during the infection cycle of phage lambda.
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Ur-lambda virions carrying intact side tail fibers adsorb to Escherichia coli host cells at a significantly higher efficiency than side-fiber-deficient lambda PaPa virions.
"84.0 ± 2.2% (6746 attached phages out of 8034 total phages in 11 experiments) of Ur-λ phages were adsorbed on E. coli host cells, significantly more than 77.3 ± 2.6% (6365 out of 8239 phages in 9 experiments) of λWT phages (Mann-Whitney U-test, p < 0.05) (Fig. 1B). This confirms that the side tail fibers help Ur-λ to encounter the host for infection."
Structural basis of bacteriophage Ur-lambda infection initiation.
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Twelve copies of the N-terminal domain of gpStf (gpStfN) form a collar enveloping the junction between the hexameric gpV ring and the hexameric gpM ring at the top of the tail tip complex.
"Twelve copies of gpStfN (gpStf-a, -b, etc.) form a collar that envelops the junction where a ring of six copies of gpV abuts a ring of six copies of gpM in the tail tip complex"
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The side tail fibers encoded by Ur-lambda stf interact with Escherichia coli OmpC and increase the rate of phage adsorption.
"These side fibers, encoded by Ur-λ stf, interact with E. coli OmpC and increase the adsorption rate"
UniProtKB entry for stf (P03764)
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gpStf forms side tail fibers that mediate primary attachment of the virion to host receptors and assembles with the tail fiber assembly protein gpTfa.
"CC -!- FUNCTION: Forms tail fibers that play a role in primary attachment of
CC virion to host receptors. Assembles with Tail fiber assembly protein to
CC form fibers attached to virion tail tip."