Model for the structure of chromatin in mammalian sperm

Journal Article · Sat May 01 04:00:00 EDT 1982 · J. Cell Biol.; (United States)

DOI:https://doi.org/10.1083/jcb.93.2.298· OSTI ID:6933732

Balhorn, R

DNA in mammalian, and most vertebrate sperm, is packaged by protamines into a highly condensed, biochemically inert form of chromatin. A model is proposed for the structure of this DNA-protamine complex which describes the site and mode of protamine binding to DNA and postulates, for the first time, specific inter- and intraprotamine interactions essential for the organization of this highly specialized chromatin. In this model, the central polyarginine segment of protamine binds in the minor groove of DNA, crosslinking and neutralizing the phosphodiester backbone of DNA while the COOH- and NH/sub 2/-terminal ends of protamine participate in the formation of inter- and intraprotamine hydrogen, hydrophobic, and disulfide bonds. Each protamine segment is of sufficient length to fill one turn of DNA, and adjacent protamines are locked in place around DNA by multiple disulfide bridges. Such an arrangement generates a neutral, insoluble chromatin complex, uses all protamine sulfhydryl groups for cross linking, conserves volume, and effectively renders the chromatin invulnerable to most extenal influences.

• Research Organization: Lawrence Livermore National Lab., CA
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6933732
• Journal Information: J. Cell Biol.; (United States), Journal Name: J. Cell Biol.; (United States) Vol. 93:82; ISSN JCLBA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
CHROMATIN
COAGULANTS
COMPLEXES
DNA
DRUGS
GAMETES
GERM CELLS
HEMATOLOGIC AGENTS
HEPARIN ANTAGONISTS
MAMMALS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
PROTAMINES
PROTEINS
SPERMATOZOA
STRUCTURAL CHEMICAL ANALYSIS
STRUCTURAL MODELS
VERTEBRATES