P2 protamines from human sperm are zinc -finger proteins with one CYS2/HIS2 motif.
P1 (HP1) and P2 (HP2, HP3, HP4) protamines were isolated from human sperm nuclei in the reduced form and their interaction with zinc and cobalt was studied. One zinc atom per molecule of P2 protamines but not of P1 protamine was found. Absorption spectra of P2 protamines with cobalt were characteristic of a tetrahedral complex involving two histidine and two cysteine residues and with one cobalt per molecule. A tetrahedral complex was found neither in P1 protamines nor in P2 protamines alkylated at cysteine or at histidine residues. The zinc finger motif Cys2/His2 of P2 protamines may play a role in stabilization of human sperm chromatin and in inhibition of transcription.
Bianchi
F
F
URA CNRS 409, Institut de Recherche sur le Cancer, Lille, France.
Rousseaux-Prevost
R
R
Sautiere
P
P
Rousseaux
J
J
D000595:Amino Acid Sequence; D001665:Binding Sites; D002851:Chromatography, High Pressure Liquid; D003553:Cystine / Q000032:analysis; D006639:Histidine / Q000032:analysis; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000302:isolation & purification; D011479:Protamines / Q000737:chemistry* / Q000302:isolation & purification; D013054:Spectrophotometry, Atomic; D013056:Spectrophotometry, Ultraviolet; D013094:Spermatozoa / Q000737:chemistry*; D015032:Zinc / Q000032:analysis; D016335:Zinc Fingers
D009687:Nuclear Proteins; D011479:Protamines; D003553:Cystine; D006639:Histidine; D015032:Zinc