ID   H2BS3_ECHES             Reviewed;          41 AA.
AC   P13283;
DT   01-JAN-1990, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 2.
DT   03-AUG-2022, entry version 57.
DE   RecName: Full=Histone H2B.3, sperm;
DE   Flags: Fragment;
OS   Echinus esculentus (Sea urchin).
OC   Eukaryota; Metazoa; Echinodermata; Eleutherozoa; Echinozoa; Echinoidea;
OC   Euechinoidea; Echinacea; Camarodonta; Echinidea; Echinidae; Echinus.
OX   NCBI_TaxID=7648;
RN   [1]
RP   PROTEIN SEQUENCE OF 2-41.
RX   PubMed=2298202; DOI=10.1111/j.1432-1033.1990.tb15288.x;
RA   Hill C.S., Thomas J.O.;
RT   "Core histone-DNA interactions in sea urchin sperm chromatin. The N-
RT   terminal tail of H2B interacts with linker DNA.";
RL   Eur. J. Biochem. 187:145-153(1990).
CC   -!- FUNCTION: Core component of nucleosome. Nucleosomes wrap and compact
CC       DNA into chromatin, limiting DNA accessibility to the cellular
CC       machineries which require DNA as a template. Histones thereby play a
CC       central role in transcription regulation, DNA repair, DNA replication
CC       and chromosomal stability. DNA accessibility is regulated via a complex
CC       set of post-translational modifications of histones, also called
CC       histone code, and nucleosome remodeling.
CC   -!- SUBUNIT: The nucleosome is a histone octamer containing two molecules
CC       each of H2A, H2B, H3 and H4 assembled in one H3-H4 heterotetramer and
CC       two H2A-H2B heterodimers. The octamer wraps approximately 147 bp of
CC       DNA.
CC   -!- SUBCELLULAR LOCATION: Nucleus. Chromosome.
CC   -!- DOMAIN: Contains 4 SPKK motifs which may interact with the minor groove
CC       of A/T-rich DNA sites. Phosphorylation of this motif may regulate DNA
CC       binding. This motif is reiterated in both termini of histone H1 and in
CC       the C-terminus of plant H2A, but its presence in the N-terminus seems
CC       to be unique to sea urchin histones H2B.
CC   -!- PTM: Monoubiquitination gives a specific tag for epigenetic
CC       transcriptional activation and is also prerequisite for histone H3
CC       'Lys-4' and 'Lys-79' methylation. {ECO:0000250}.
CC   -!- PTM: Phosphorylated on SPKK motifs 3 and 4; which may regulate DNA
CC       binding. Dephosphorylated during maturation of spermatids to mature
CC       sperm and rephosphorylated at fertilization (By similarity).
CC       {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the histone H2B family. {ECO:0000305}.
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DR   PIR; S07769; S07769.
DR   AlphaFoldDB; P13283; -.
DR   SMR; P13283; -.
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.
PE   1: Evidence at protein level;
KW   Chromosome; Direct protein sequencing; DNA-binding; Nucleosome core;
KW   Nucleus; Phosphoprotein; Ubl conjugation.
FT   INIT_MET        1
FT                   /note="Removed"
FT                   /evidence="ECO:0000269|PubMed:2298202"
FT   CHAIN           2..>41
FT                   /note="Histone H2B.3, sperm"
FT                   /id="PRO_0000071885"
FT   REGION          1..41
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   MOTIF           4..7
FT                   /note="SPKK motif 1"
FT   MOTIF           9..12
FT                   /note="SPKK motif 2"
FT   MOTIF           14..17
FT                   /note="SPKK motif 3"
FT   MOTIF           19..22
FT                   /note="SPKK motif 4"
FT   COMPBIAS        14..41
FT                   /note="Basic residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   MOD_RES         14
FT                   /note="Phosphoserine"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         19
FT                   /note="Phosphoserine"
FT                   /evidence="ECO:0000250"
FT   NON_TER         41
SQ   SEQUENCE   41 AA;  4316 MW;  6C54FD9F5B121348 CRC64;
     MPRSPSKSSP KKGSPRKASP KRGGKGAKRA GKGGRRRTVV K