Covalent Structure of Calf‐Thymus ALK‐Histone

The complete amino acid sequence (124 residues) of histone H2A from gonads of the starfish Asterius ruhens has been established from automated sequence analyses of large fragments obtained by staphylococcal protease digestion of histone H2A and by limited hydrolysis of H2A-H2B complex with mouse submaxillary gland protease and from structural studies of peptides generated by enzymatic hydrolyses of these fragments or of the protein.By comparison with calf homologous histone, the starfish histone H2A shows 5 deletions and 12 substitutions. Half of the substitutions are non-conservative.Microheterogeneities were found at positions 18, 40 and 50 and result in the existence of at least two variants of starfish gonad histone H2A.Structural studies of histones H2A from different species widely separated on the evolutionary scale [I -61 have shown that extensive structural modifications (point mutations, deletions and insertions) mainly occur in the highly basic N-terminal and C-terminal parts of the protein. The central region of the molecule (residues 18-118), which strongly interacts with the region 32-125 of histone H2B to form the dimer H2A-H2B in the nucleosome, appears generally conserved during evolution.The higher degree of variability of histone H2B in Echinidae [7], one of the three families of the echinoderms has led us to investigate the primary structure of both histones H2A and H2B in Asterinidae.In this paper we report the complete amino acid sequence of histone H2A from gonads of the starfish Asterias ruhens.

Section: Discussionmentioning

confidence: 99%

Section: Gi U Lys (Oh)mentioning

confidence: 99%

See 1 more Smart Citation

Primary Structure of Histone H2A from Gonads of the Starfish Asterias rubens

Martinage

Bélaïche

Dupressoir

et al. 1983

“…Primary structural studies of histone H2A from vertebrates: calf [4], rat [5], chicken [6] and from marine invertebrates [7 -101 show that most of the structural changes (point mutations, deletions) occur in the highly basic aminoterminal and carboxy-terminal parts of the protein.…”

mentioning

confidence: 99%

Primary structure of histone H2B from gonads of the starfish Asterias rubens

Martinage

Briand

et al. 1985

The complete amino acid sequence (121 residues) of histone H2B from gonads of the starfish Asterias rubens has been established from structural data obtained essentially from large fragments generated by cleavage of histone H2B at aspartyl residues and by limited hydrolysis of the dimer H2A-H2B with mouse submaxillary gland protease.No real sequence homology can be found between the amino-terminal sequence (residues 1-21) of starfish and calf H2B. One non-conservative substitution (serine-32 in calf + lysine-28 in starfish) leads to the presence of a cluster of eight basic residues (sequence 23 -30) and to the disappearance of a potential site of phosphorylation.A particular structural feature of starfish histone H2B is the presence of N-dimethylproline at its aminoterminal end. By comparison with N-terminal acetylation, which is commonly found in histones, N-terminal methylation is rarely observed. At the present time the functional significance of the N-terminal methylation as well as that of the proline-rich nature of the amino-terminal sequence of the starfish histone H2B remain to be defined.The amino acid sequences of core particle histones were first determined for calf thymus, then in a variety of tissues and species [l] [21] and found to be located in the N-terminal region.The peculiar structural characteristics and the higher degree of variability observed in histone H2B from Echinidae [I] have led us to investigate the primary structure of histone H2B in Asterinidae, another family of the phylum echinoderms.In this paper we report the complete amino acid sequence of histone H2B from gonads of the starfish Asterias rubens. This sequence was established from structural data provided by tryptic peptides and large fragments derived from cleavage of the protein at aspartic acid and arginine residues.Starfish histone H2B is devoid of a free amino-terminal group. The blocking group has been identified as dimethylproline. The amino-terminal blocking of histones by methylation has only been observed previously in Tetrahymena histone H2B [22]. MATERIALS AND METHODS MaterialsMature starfish were obtained from the Station Marine, Wimereux (France). After excision, gonads were frozen in solid C 0 2 and kept at -20" C until use.Trypsin (treated with TosPheCH2C1) and carboxypeptidases A and B (treated with PhMeS0,F) were obtained from Worthington. Thermolysin was from Merck. Arg-C endoproteinase from mouse submaxillaris gland was purchased from Boehringer.Dimethylallylamine, propan-1 -01, dithioerythritol and anhydrous hydrazine were sequanal grade from Pierce. Benzene and chloro-1 -butane for sequential analysis were purchased from SDS (Peypin, France). Phenylisothiocyanate, heptane and heptafluorobutyric acid were sequanal grade from Merck. Polybrene was purchased from Aldrich and the dipeptide GlyGly from Sigma. All other reagents were of the highest purity available.Isolation of histone H2B and of histone dimer H2A-H2BChromatin was isolated from gonads as described in [23]. The crude fraction F2b was extracted...

“…Structural studies of histones H2B from different species widely separated on the evolutionary scale [3-111 have shown that extensive structural changes (point mutations, deletions and insertions) occur mainly in the amino-terminal part of the molecule. On the other hand, the carboxy two-thirds of the protein have been highly conserved during evolution.Similarly the structural variations of histone H2A have been studied in our laboratory for many years, in a number of species taken among vertebrates: calf [12,13], rat [14], chicken [l 51 : and marine invertebrates: sea-urchin [16], starfish, cuttlefish and sipunculus. These studies show that most of the changes occur in the highly basic amino-terminal and carboxy-terminal parts of the protein: the central region of the niolcule (residues 18-l I S ) , which is involved in strong protein-protein interactions between histones H2A and H2B, is highly conserved from species to species.…”

mentioning

confidence: 99%

The Amino‐Acid Sequence of Histone H2A from Cuttlefish Sepia officinalis

Wouters-Tyrou

Martin-Ponthieu

Briand

et al. 1982

The amino acid sequence of cuttlefish testis histone H2A (124 residues) was establijhed from structural data obtained by automated sequencing of large peptides generated by the cleavage ot' the protein with VY staphylococcal protease or by limited chymotryptic hydrolysis.Compared to the calf thymus homologous histone, cuttlefish H2A shows 14 substirutions (most of them conservative) and 5 deletions.Extensive evolutionary changes were mainly observed in the basic amino-terminal and carboxy-terminal regions of the molecule, which are the primary DNA-binding sites. Few punctual changes are observed in the central region (residues 18-118), which interacts strongly with histone H2B to form the diiner H2A-H2B.In the core particle histones H2A and H2B appear more variable throughout evolution than histones H3 and H4 (for recent reviews, see [I, 21). Structural studies of histones H2B from different species widely separated on the evolutionary scale [3-111 have shown that extensive structural changes (point mutations, deletions and insertions) occur mainly in the amino-terminal part of the molecule. On the other hand, the carboxy two-thirds of the protein have been highly conserved during evolution.Similarly the structural variations of histone H2A have been studied in our laboratory for many years, in a number of species taken among vertebrates: calf [12,13], rat [14], chicken [l 51 : and marine invertebrates: sea-urchin [16], starfish, cuttlefish and sipunculus. These studies show that most of the changes occur in the highly basic amino-terminal and carboxy-terminal parts of the protein: the central region of the niolcule (residues 18-l I S ) , which is involved in strong protein-protein interactions between histones H2A and H2B, is highly conserved from species to species.Cuttlefish and sipunculus are located on the branch of an evolutionary tree which led to insects whereas echinoderms are located on the branch which led to vertebrates [17].Cuttlefish (Sclpiu officinalis) is a cephalopod which exhibits an intermediary type of evolution. It is, in some ways, closer to vertebrates than to other marine invertebrates, such as echinoderms : the testis is well differentiated and the organisation of the eye, for example, is highly elaborated.Here we present the amino acid sequence of histone H2A from cuttlefish testis. The alignment of the 124 residues of cuttlefish histone H2A was established from the structural data obtained essentially from large peptides generated by hydrolysis or the protein with VS staphylococcal protease and chymotrypsin.