4do2
From Proteopedia
Crystal Structure of the Rop protein mutant D30P/A31G at resolution 1.4 resolution.
Structural highlights
Function[ROP_ECOLX] Regulates plasmid DNA replication by modulating the initiation of transcription of the primer RNA precursor. Processing of the precursor of the primer, RNAII, is inhibited by hydrogen bonding of RNAII to its complementary sequence in RNAI. ROP increases the affinity of RNAI for RNAII and thus decreases the rate of replication initiation events. Publication Abstract from PubMedThe dimeric Repressor of Primer (Rop) protein, a widely used model system for the study of coiled-coil 4-alpha-helical bundles, is characterized by a remarkable structural plasticity. Loop region mutations lead to a wide range of topologies, folding states, and altered physicochemical properties. A protein-folding study of Rop and several loop variants has identified specific residues and sequences that are linked to the observed structural plasticity. Apart from the native state, native-like and molten-globule states have been identified; these states are sensitive to reducing agents due to the formation of nonnative disulfide bridges. Pro residues in the loop are critical for the establishment of new topologies and molten globule states; their effects, however, can be in part compensated by Gly residues. The extreme plasticity in the assembly of 4-alpha-helical bundles reflects the capacity of the Rop sequence to combine a specific set of hydrophobic residues into strikingly different hydrophobic cores. These cores include highly hydrated ones that are consistent with the formation of interchain, nonnative disulfide bridges and the establishment of molten globules. Potential applications of this structural plasticity are among others in the engineering of bio-inspired materials. Structural plasticity of 4-alpha-helical bundles exemplified by the puzzle-like molecular assembly of the Rop protein.,Amprazi M, Kotsifaki D, Providaki M, Kapetaniou EG, Fellas G, Kyriazidis I, Perez J, Kokkinidis M Proc Natl Acad Sci U S A. 2014 Jul 29;111(30):11049-54. doi:, 10.1073/pnas.1322065111. Epub 2014 Jul 14. PMID:25024213[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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