Staphylococcal nuclease: Sequential assignments and solution structure

Journal Article · Tue Jun 27 04:00:00 EDT 1989 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00439a028· OSTI ID:5084947

Torchia, D A; Sparks, S W; Bax, A ^[1]

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1. National Institutes of Health, Bethesda, MD (USA)

Sequential assignments are reported for backbone {sup 15}N and {sup 1}H of nearly all residues of staphylococcal nuclease (Nase) complexed with thymidine 3{prime},5{prime}-diphosphate and Ca{sup 2+}. Because of the relatively large size of the Nase ternary complex, M{sub r} 18K, the crucial element of our assignment strategy was the use of isotope-edited two-dimensional NMR spectra, particularly {sup 15}N-edited nuclear Overhauser enhancement spectroscopy (NOESY), {sup 15}N-edited J-correlated spectroscopy (COSY), and {sup 1}H/{sup 15}N or {sup 1}H/{sup 13}C heteronuclear multiple quantum shift correlation spectroscopy (HMQC). These experiments, together with the more conventional NOESY, COSY, and homonuclear Hartmann-Hahn spectra of natural abundance or deuteriated samples, yielded backbone assignments of 127 of the 136 residues in the structured part of the protein. Using the NOESY data, the authors identified three helical domains and several {beta}-sheets which were in close correspondence with secondary structure identified in the crystal structure. Moreover, many long-range NOESY connectivities were identified that were in agreement with distances derived from the crystal structure. The region of the sequence in the neighborhood of residue 50 appears to be more flexible and disordered in solution than in the crystal. Very slowly exchanging amide protons are those found to be hydrogen bonded in the crystal structure; however, even hydrogen-bonded amides located within similar types of regular secondary structures, e.g., {alpha}-helices, exchange with greatly different rates.

• OSTI ID: 5084947
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 28:13; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMMONIUM CHLORIDES
AMMONIUM COMPOUNDS
AMMONIUM HALIDES
BACTERIA
BARYONS
CHLORIDES
CHLORINE COMPOUNDS
ELEMENTARY PARTICLES
ENZYMES
ESTERASES
FERMIONS
HADRONS
HALIDES
HALOGEN COMPOUNDS
HEAVY WATER
HYDROGEN COMPOUNDS
HYDROLASES
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MICROORGANISMS
MOLECULAR STRUCTURE
NITROGEN 15
NITROGEN ISOTOPES
NUCLEAR MAGNETIC RESONANCE
NUCLEASES
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
OVERHAUSER EFFECT
OXYGEN COMPOUNDS
PHOSPHODIESTERASES
PROTONS
RESONANCE
STABLE ISOTOPES
STAPHYLOCOCCUS
WATER