1QX8

Crystal structure of a five-residue deletion mutant of the Rop protein

Summary for 1QX8

• Entry DOI: 10.2210/pdb1qx8/pdb
• Related: 1B6Q 1GMG 1ROP 1RPO
• Descriptor: Regulatory protein ROP (2 entities in total)
• Functional Keywords: replication; initiation of transcription; rna primer; x-ray, transcription
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 13357.09

Authors

Glykos, N.M.,Vlassi, M.,Papanikolaou, Y.,Kotsifaki, D.,Cesareni, G.,Kokkinidis, M. (deposition date: 2003-09-04, release date: 2004-09-28, Last modification date: 2023-08-23)

Primary citation

Glykos, N.M.,Papanikolau, Y.,Vlassi, M.,Kotsifaki, D.,Cesareni, G.,Kokkinidis, M.
Loopless Rop: structure and dynamics of an engineered homotetrameric variant of the repressor of primer protein.
Biochemistry, 45:10905-10919, 2006

PubMed Abstract: The repressor of primer (Rop) protein has become a steady source of surprises concerning the relationship between the sequences and the structures of several of its mutants and variants. Here we add another piece to the puzzle of Rop by showing that an engineered deletion mutant of the protein (corresponding to a deletion of residues 30-34 of the wild-type protein and designed to restore the heptad periodicity at the turn region) results in a complete reorganization of the bundle which is converted from a homodimer to a homotetramer. In contrast (and as previously shown), a two-residue insertion, which also restores the heptad periodicity, is essentially identical with wild-type Rop. The new deletion mutant structure is a canonical, left-handed, all-antiparallel bundle with a completely different hydrophobic core and distinct surface properties. The structure agrees and qualitatively explains the results from functional, thermodynamic, and kinetic studies which indicated that this deletion mutant is a biologically inactive hyperstable homotetramer. Additional insight into the stability and dynamics of the mutant structure has been obtained from extensive molecular dynamics simulations in explicit water and with full treatment of electrostatics.

PubMed: 16953576
DOI: 10.1021/bi060833n

Experimental method

X-RAY DIFFRACTION (2.02 Å)