Gene. 98 (1991) 299-300

299

Elsevier

GENE

03880

Brief Notes Nucleotide sequence of a member of the chicken H2B histone-encoding (H2B-specific

element;

T. Nakayama

and Y. Setoguchi

Department

of Biochemistry,

recombinant

DNA;

Miycazaki Medic&

Received by H. Yoshikawa: 3 September Accepted: 23 September 1990

H2B protein

College, Kihara,

gene family

variants)

Kiyocake. Miyazaki,

889-l 6 (Japan)

1990

SUMMARY

The nucleotide sequence of a gene from the chicken H2B histone-encoding gene family has been determined. Our endings, together with those in a previous paper [Grandy and Dodgson, Nucleic Acids Res. 1.5 (1987) 1063-IOSO], show that the seven H2B genes encode three different histone variants. __.-. -. -__

There exist from about ten to several hundred genes of each histone subfamily per haploid genome in most multicellular organisms. However, chickens appear to have one of the lowest gene repetitive frequencies ranging from six for the HI genes to 8-10 for the core histone genes (H2A, H2B, H3, and H4) (Ruiz-C~rillo et al., 1983; Sugarm~ et al., 1983; D’Andrea et al., 1985; Coles et al., 1987; Grandy and Dodgson, 1987). The H2B gene family contains eight highly homologous members, designated H2B-Z to H2B- YZZZ,which fall into two major histone-encoding gene clusters (Grandy and Dodgson, 1987). Six of the eight genes (HZ&Z, HZB-ZZ, H2&ZZZ, HZ&IV, H2S-VZ, and H2B- VZZ) have been completely sequenced, whereas one of them (H2B-I/) has been partially sequenced and another gene (H2B- VZIZ) still remains to be characterized. In order to understand how each H2B gene individually regulates its self-expression, it is essential to know the complete nt sequences including the 5’-flanking regions of all of the genes. Thus the complete nt sequence of H2B-V, only a 3’ part of which had been sequenced, was determined and presented here. fiorrrf~,otri/r12ce 10; Dr. T. Nakayama, Miyazaki

Medical

College, Kihara,

Tel. (81.OY85)85-3127; Abbreviatmns: encoding H.

Department

Kiyotake.

Miyazakl,

of Biochemistry, 889-16 (Japan)

Fax (81-09X5)85-6503.

aa. amino acid(s); nt, nucicotide(s):

H, histone; H, gene(s)

The analysis of the 5’4anking sequence reveals that HZB-I/, like the other genes in the family, possesses an H2B-specific element of the form 5’-CTTTGCATA from nt positions -103 to -96, in addition to the common CCAAT and TATA boxes (Fig. 1). Additionally. the coding region of the gene is 375 nt long and codes for protein composed of 125 aa similar in size to the others (Grandy and Dodgson, 1987). Codon 122 (ACC) in our sample codes for Thr, whereas codon 122 (ATC) containing T as the second nt, described by Grandy and Dodgson (1987), codes for Ile. Codon 122 in the other six H2B genes is ACC exclusively coding for Thr. It is unlikely that the aa sequence predicted from the same H2B gene differs among the individual chickens used. Thus, it seems most likely that the nt at position t 368 of H2B-V is C and the predicted aa at position 122 is Thr, like the other genes in the H2B gene family. Interestingly, the aa predicted from codon 30 (CGA) of H2B- V, which was not available in the previous paper of Grandy and Dodgson (1987). is Arg. Codon 30 of the other six H2B genes is AAG and encode Lys. Our results, together with those of Grandy and Dodgson (1987), indicate that the seven H2B genes code for three different protein variants whose aa sequences differ from 1 to 3 residues each. Five H2B genes (H2B-I, H2B-ZZ, H2B-ZZZ, H2B-I V, and H2B-VI) code for the same aa sequence (class I). H2B-VIZ is the most different gene and contains three aa alterations (Lys3’ -+ Arg, SerX2 + Ala, and Glyh” + Ser)

300

Fig. f The nr sequence

of HZ&V

and deduced

Met. and those on the 5’ side of nt

aa sequence.

1 are indicated

The H2B-specific

element of the forms, CTTTGCATA,

report

and Dodgson

of Crandy

The nt are numbered

by negative

(1087)was available

numbers.

is double-underlined. ot~ly Finns

nt + 107 to

(class II) relative to cfass I. H2B- V, which is now cofllpietely sequenced by us (Fig. l), contains a single aa change (Lys’” --f Arg) (class III) relative to class 1. The GenBank accession number of this sequence is M57901.

beginning

The consensus Asterisks

with the firsr ATG triplet enwdmg

sequences,

CCAAT

a putatlw

~mttawn

and TATA boxes. are sinpic-underlined.

nt sequence of HZB-V in the previous

mark the stop codon. The

t 380.

D’Amirm, R.J.. C&s,

L.S., Lesmkowski,

Chromosomni

organization

ciations

inverted

and

C., f‘abe. L. and \%‘riis, J.R.E.:

ofchicken

histone genes: preferred

duplications.

Mol.

Cell.

Biol.

asso-

5 (1985)

3108-3115. Grandy,

D.K.

chicken

and Dodgson,

H2B

histnne

gene

J.B.: Structure family.

and organization

Nucleic

Acids

Res.

of the 15 (19X7)

1053-1080. REFERENCES

Ruiz-Carriilo.

A., Affoiter,

M. and Renaud,

f.: Genumic

the genes coding for the six main histones Coles, L.S., Robins,

A.J., Madley,

tion of the chicken

histone

complete set of vertebrate ( 1987) 9656-9663.

1.X

and Wells, J.R.k

Hl gene complement. HI protein

sequences.

CharacterizaGeneration

of a

J. 8101. Chem. 262

organization

of the chickens:

of

complete

sequence of the H5 gene. J. Mol. Biol. 170 (1983) 843-8.59. Sugarman, B.J., Dodgson, J.B. and Engel, J.D.: Genomic organization, DNA sequence,

and expression

of chickenembryonic

J. Biol. Chem. 258 (1983) 9005-90

16.

histone genes,