1L34

HIGH-RESOLUTION STRUCTURE OF THE TEMPERATURE-SENSITIVE MUTANT OF PHAGE LYSOZYME, ARG 96 (RIGHT ARROW) HIS

Summary for 1L34

• Entry DOI: 10.2210/pdb1l34/pdb
• Related: 1L01 1L02 1L03 1L04 1L05 1L06 1L07 1L08 1L09 1L10 1L11 1L12 1L13 1L14 1L15 1L16 1L17 1L18 1L19 1L20 1L21 1L22 1L23 1L24 1L25 1L26 1L27 1L28 1L29 1L30 1L31 1L32 1L33 1L35 1L36 2LZM
• Descriptor: T4 LYSOZYME (2 entities in total)
• Functional Keywords: hydrolase (o-glycosyl)
• Biological source: Enterobacteria phage T4
• Total number of polymer chains: 1
• Total formula weight: 18643.42

Authors

Weaver, L.H.,Matthews, B.W. (deposition date: 1989-05-01, release date: 1990-01-15, Last modification date: 2024-05-22)

Primary citation

Weaver, L.H.,Gray, T.M.,Grutter, M.G.,Anderson, D.E.,Wozniak, J.A.,Dahlquist, F.W.,Matthews, B.W.
High-resolution structure of the temperature-sensitive mutant of phage lysozyme, Arg 96----His.
Biochemistry, 28:3793-3797, 1989

PubMed Abstract: The structure of the temperature-sensitive mutant lysozyme of bacteriophage T4 in which arginine 96 is replaced by histidine has been determined crystallographically and refined to a residual of 17.6% at 1.9-A resolution. Overall, the three-dimensional structure of the mutant protein is extremely similar to that of wild type. There are local distortions in the mutant structure suggesting that the substituted His 96 residue is under strain. This appears to be one of the major reasons for the decreased thermostability. In wild-type lysozyme the guanidinium of Arg 96 is located at the carboxy terminus of alpha-helix 82-90 and makes a pair of hydrogen bonds to two of the carbonyl groups in the last turn of the helix. The loss of this "helix dipole" interaction also appears to contribute to the destabilization. The pKa* of His 96 in the mutant lysozyme has been determined by nuclear magnetic resonance and found to be 6.8 at 10 degrees C. This relatively normal value of the histidine pKa* suggests that the protonated and unprotonated forms of the imidazole ring are perturbed equally by the protein environment or, what is equivalent, the mutant lysozyme is equally stable with either histidine species.

PubMed: 2665808
DOI: 10.1021/bi00435a025

Experimental method

X-RAY DIFFRACTION (1.9 Å)