ID   PRTB_ACIGU              Reviewed;          27 AA.
AC   P69006; P02323;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   25-MAY-2022, entry version 28.
DE   RecName: Full=Protamine-B;
DE   AltName: Full=Sturine-B;
OS   Acipenser gueldenstaedtii (Russian sturgeon) (Danube sturgeon).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Actinopterygii; Chondrostei; Acipenseriformes; Acipenseridae; Acipenser.
OX   NCBI_TaxID=7902;
RN   [1]
RP   PROTEIN SEQUENCE.
RA   Yulikova E.P., Evseenko L.K., Baratova L.A., Belyanova L.P., Rybin V.K.,
RA   Silaev A.B.;
RT   "The primary structure of sturine B, a protamine from Caspian sturgeon.";
RL   Bioorg. Khim. 2:1613-1617(1976).
CC   -!- FUNCTION: Protamines substitute for histones in the chromatin of sperm
CC       during the haploid phase of spermatogenesis. They compact sperm DNA
CC       into a highly condensed, stable and inactive complex.
CC   -!- SUBCELLULAR LOCATION: Nucleus. Chromosome.
CC   -!- TISSUE SPECIFICITY: Testis.
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DR   PIR; A02665; SRAPC.
DR   AlphaFoldDB; P69006; -.
DR   GO; GO:0000786; C:nucleosome; IEA:UniProtKB-KW.
DR   GO; GO:0005634; C:nucleus; IEA:UniProtKB-SubCell.
DR   GO; GO:0003677; F:DNA binding; IEA:UniProtKB-KW.
DR   GO; GO:0030154; P:cell differentiation; IEA:UniProtKB-KW.
DR   GO; GO:0030261; P:chromosome condensation; IEA:UniProtKB-KW.
DR   GO; GO:0007283; P:spermatogenesis; IEA:UniProtKB-KW.
PE   1: Evidence at protein level;
KW   Chromosome; Developmental protein; Differentiation;
KW   Direct protein sequencing; DNA condensation; DNA-binding; Nucleosome core;
KW   Nucleus; Spermatogenesis.
FT   PEPTIDE         1..27
FT                   /note="Protamine-B"
FT                   /id="PRO_0000044303"
FT   REGION          1..27
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
SQ   SEQUENCE   27 AA;  3707 MW;  E300B46B1737EC80 CRC64;
     ARRRRRSSRP QRRRRRRRHG RRRRGRR