The nonspecific DNA-binding and -bending proteins HMG1 and HMG2 promote the assembly of complex nucleoprotein structures.

The mammalian high mobility group proteins HMG1 and HMG2 are abundant, chromatin-associated proteins whose cellular function is not known. In this study we show that these proteins can substitute for the prokaryotic DNA-bending protein HU in promoting the assembly of the Hin invertasome, an intermediate structure in Hin-mediated site-specific DNA inversion. Formation of this complex requires the assembly of the Hin recombinase, the Fis protein, and three cis-acting DNA sites, necessitating the looping of intervening DNA segments. Invertasome assembly is strongly stimulated by HU or HMG proteins when one of these segments is shorter than 104 bp. By use of ligase-mediated circularization assays, we demonstrate that HMG1 and HMG2 can bend DNA extremely efficiently, forming circles as small as 66 bp, and even 59-bp circles at high HMG protein concentrations. In both invertasome assembly and circularization assays, substrates active in the presence of HMG1 contain one less helical turn of DNA compared with substrates active in the presence of HU protein. Analysis of different domains of HMG1 generated by partial proteolytic digestion indicate that DNA-binding domain B is sufficient for both bending and invertasome assembly. We suggest that an important biological function of HMG1 and HMG2 is to facilitate cooperative interactions between cis-acting proteins by promoting DNA flexibility. A general role for HMG1 and HMG2 in chromatin structure is also suggested by their ability to wrap DNA duplexes into highly compact forms.

[1]  M. Haykinson,et al.  DNA looping and the helical repeat in vitro and in vivo: effect of HU protein and enhancer location on Hin invertasome assembly. , 1993, The EMBO journal.

[2]  P. Kraulis,et al.  Structure of the HMG box motif in the B‐domain of HMG1. , 1993, The EMBO journal.

[3]  M. Beltrame,et al.  Protein HU binds specifically to kinked DNA , 1993, Molecular microbiology.

[4]  S. Goodman,et al.  Deformation of DNA during site-specific recombination of bacteriophage lambda: replacement of IHF protein by HU protein or sequence-directed bends. , 1992, Proceedings of the National Academy of Sciences of the United States of America.

[5]  P N Goodfellow,et al.  SRY, like HMG1, recognizes sharp angles in DNA. , 1992, The EMBO journal.

[6]  Dimitris Thanos,et al.  The High Mobility Group protein HMG I(Y) is required for NF-κB-dependent virus induction of the human IFN-β gene , 1992, Cell.

[7]  T. Baker,et al.  DNA-promoted assembly of the active tetramer of the Mu transposase. , 1992, Genes & development.

[8]  P. Hagerman.  Straightening out the bends in curved DNA. , 1992, Biochimica et biophysica acta.

[9]  D. Lilley.  HMG has DNA wrapped up , 1992, Nature.

[10]  S. Lippard,et al.  Specific binding of chromosomal protein HMG1 to DNA damaged by the anticancer drug cisplatin. , 1992, Science.

[11]  Rudolf Grosschedl,et al.  The HMG domain of lymphoid enhancer factor 1 bends DNA and facilitates assembly of functional nucleoprotein structures , 1992, Cell.

[12]  D. Lilley,et al.  The DNA binding site of HMG1 protein is composed of two similar segments (HMG boxes), both of which have counterparts in other eukaryotic regulatory proteins. , 1992, The EMBO journal.

[13]  M. Parisi,et al.  DNA wrapping and bending by a mitochondrial high mobility group-like transcriptional activator protein. , 1992, The Journal of biological chemistry.

[14]  J. Diffley,et al.  DNA binding properties of an HMG1-related protein from yeast mitochondria. , 1992, The Journal of biological chemistry.

[15]  R Grosschedl,et al.  DNA-binding properties of the HMG domain of the lymphoid-specific transcriptional regulator LEF-1. , 1991, Genes & development.

[16]  R. C. Johnson.  Mechanism of site-specific DNA inversion in bacteria. , 1991, Current opinion in genetics & development.

[17]  J. Diffley,et al.  A close relative of the nuclear, chromosomal high-mobility group protein HMG1 in yeast mitochondria. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[18]  R. C. Johnson,et al.  Configuration of DNA strands and mechanism of strand exchange in the Hin invertasome as revealed by analysis of recombinant knots. , 1991, Genes & development.

[19]  D. Bastia,et al.  Cooperativity at a distance promoted by the combined action of two replication initiator proteins and a DNA bending protein at the replication origin of pSC101. , 1991, Genes & development.

[20]  R. C. Johnson,et al.  Identification of two functional regions in Fis: the N‐terminus is required to promote Hin‐mediated DNA inversion but not lambda excision. , 1991, The EMBO journal.

[21]  Sunghoon Kim,et al.  Mapping of a higher order protein-DNA complex: Two kinds of long-range interactions in λ attL , 1990, Cell.

[22]  S. Kustu,et al.  The integration host factor stimulates interaction of RNA polymerase with NIFA, the transcriptional activator for nitrogen fixation operons , 1990, Cell.

[23]  L. Shapiro,et al.  Integration host factor is required for the activation of developmentally regulated genes in Caulobacter. , 1990, Genes & development.

[24]  R. C. Johnson,et al.  The Hin invertasome: protein-mediated joining of distant recombination sites at the enhancer. , 1990, Science.

[25]  D. Landsman,et al.  Structural features of the HMG chromosomal proteins and their genes. , 1990, Biochimica et biophysica acta.

[26]  N. Cozzarelli,et al.  Processive recombination by the phage Mu Gin system: Implications for the mechanisms of DNA strand exchange, DNA site alignment, and enhancer action , 1990, Cell.

[27]  J. Singh,et al.  High mobility group proteins 1 and 2 function as general class II transcription factors. , 1990, Biochemistry.

[28]  T. Baker,et al.  Strand separation required for initiation of replication at the chromosomal origin of E.coli is facilitated by a distant RNA–DNA hybrid. , 1990, The EMBO journal.

[29]  Robert Tjian,et al.  Nucleolar transcription factor hUBF contains a DNA-binding motif with homology to HMG proteins , 1990, Nature.

[30]  G. Chaconas,et al.  Immunoelectron microscopic analysis of the A, B, and HU protein content of bacteriophage Mu transpososomes. , 1990, The Journal of biological chemistry.

[31]  A. Klug,et al.  2 Bending of DNA in Nucleoprotein Complexes , 1990 .

[32]  Record Mt,et al.  Stable DNA Loops in Vivo and in Vitro: Roles in Gene Regulation at a Distance and in Biophysical Characterization of DNA , 1990 .

[33]  M. Record,et al.  Stable DNA loops in vivo and in vitro: roles in gene regulation at a distance and in biophysical characterization of DNA. , 1990, Progress in nucleic acid research and molecular biology.

[34]  M. Yoshida,et al.  Efficient large-scale purification of non-histone chromosomal proteins HMG1 and HMG2 by using Polybuffer-exchanger PBE94. , 1990, Journal of chromatography.

[35]  Steven D. Goodman,et al.  Functional replacement of a protein-induced bend in a DNA recombination site , 1989, Nature.

[36]  P. Hagerman,et al.  DNA ring closure mediated by protein HU. , 1989, The Journal of biological chemistry.

[37]  G. Schroth,et al.  Transcription factor IIIA induced bending of the Xenopus somatic 5S gene promoter , 1989, Nature.

[38]  A. Toussaint,et al.  Multiple defects in Escherichia coli mutants lacking HU protein , 1989, Journal of bacteriology.

[39]  L. Sheflin,et al.  High mobility group protein 1 preferentially conserves torsion in negatively supercoiled DNA. , 1989, Biochemistry.

[40]  S. Kim,et al.  DNA looping generated by DNA bending protein IHF and the two domains of lambda integrase , 1989, Science.

[41]  H. Nash,et al.  The interaction of E. coli IHF protein with its specific binding sites , 1989, Cell.

[42]  R C Johnson,et al.  Intermediates in Hin‐mediated DNA inversion: a role for Fis and the recombinational enhancer in the strand exchange reaction. , 1989, The EMBO journal.

[43]  M. Beltrame,et al.  Specific recognition of cruciform DNA by nuclear protein HMG1. , 1989, Science.

[44]  G. Reeck,et al.  A human placental cDNA clone that encodes nonhistone chromosomal protein HMG-1. , 1989, Nucleic acids research.

[45]  S. Adhya,et al.  Multipartite genetic control elements: communication by DNA loop. , 1989, Annual review of genetics.

[46]  D. Tremethick,et al.  Effects of high mobility group proteins 1 and 2 on initiation and elongation of specific transcription by RNA polymerase II in vitro. , 1988, Nucleic acids research.

[47]  T. Okazaki,et al.  Construction and characterization of the deletion mutant of hupA and hupB genes in Escherichia coli. , 1988, Journal of molecular biology.

[48]  D. J. Kaplan,et al.  Full length cDNA sequence for bovine high mobility group 1 (HMG1) protein. , 1988, Nucleic acids research.

[49]  J. F. Thompson,et al.  Empirical estimation of protein-induced DNA bending angles: applications to lambda site-specific recombination complexes. , 1988, Nucleic acids research.

[50]  D. Pettijohn,et al.  Histone-like proteins and bacterial chromosome structure. , 1988, The Journal of biological chemistry.

[51]  E. Alexandrova,et al.  Acetylated HMG1 protein interacts specifically with homologous DNA polymerase alpha in vitro. , 1988, Biochemical and biophysical research communications.

[52]  C. Astell,et al.  Interaction of the mouse chromosomal protein HMG-I with the 3' ends of genes in vitro. , 1988, The Journal of biological chemistry.

[53]  H. Nash,et al.  Bending of the bacteriophage lambda attachment site by Escherichia coli integration host factor. , 1988, The Journal of biological chemistry.

[54]  G. Dixon,et al.  Induction by torsional stress of an altered DNA conformation 5' upstream of the gene for a high mobility group protein from trout and specific binding to flanking sequences by the gene product HMG-T. , 1988, Biochemistry.

[55]  N. Kleckner,et al.  Tn10 transposition and circle formation in vitro , 1987, Cell.

[56]  K. Drlica,et al.  Histonelike proteins of bacteria. , 1987, Microbiological reviews.

[57]  D. Dripps,et al.  DNA bending induced by the catabolite activator protein allows ring formation of a 144 bp DNA. , 1987, Journal of biomolecular structure & dynamics.

[58]  F. Blattner,et al.  Direct evidence for DNA bending at the lambda replication origin. , 1987, Science.

[59]  L. A. Kohlstaedt,et al.  Non-histone chromosomal protein HMG1 modulates the histone H1-induced condensation of DNA. , 1987, The Journal of biological chemistry.

[60]  M. Yoshida.  High glutamic and aspartic region in nonhistone protein HMG(1+2) unwinds DNA double helical structure. , 1987, Journal of biochemistry.

[61]  H. Nash,et al.  The interaction of recombination proteins with supercoiled DNA: Defining the role of supercoiling in lambda integrative recombination , 1986, Cell.

[62]  H. Echols,et al.  Multiple DNA-protein interactions governing high-precision DNA transactions. , 1986, Science.

[63]  Mark Ptashne,et al.  Gene regulation by proteins acting nearby and at a distance , 1986, Nature.

[64]  M. Simon,et al.  Host protein requirements for in vitro site-specific DNA inversion , 1986, Cell.

[65]  D. Tremethick,et al.  High mobility group proteins 1 and 2 stimulate transcription in vitro by RNA polymerases II and III. , 1986, The Journal of biological chemistry.

[66]  T. Baker,et al.  Extensive unwinding of the plasmid template during staged enzymatic initiation of DNA replication from the origin of the Escherichia coli chromosome , 1986, Cell.

[67]  H. Buc,et al.  Variations of intramolecular ligation rates allow the detection of protein‐induced bends in DNA. , 1986, The EMBO journal.

[68]  M. Solomon,et al.  A mammalian high mobility group protein recognizes any stretch of six A.T base pairs in duplex DNA. , 1986, Proceedings of the National Academy of Sciences of the United States of America.

[69]  J. Brown,et al.  The binding of the chromosomal protein HMG-2a to DNA regions of reduced stabilities. , 1986, The Journal of biological chemistry.

[70]  K. Mizuuchi,et al.  A defined system for the DNA strand-transfer reaction at the initiation of bacteriophage Mu transposition: protein and DNA substrate requirements. , 1985, Proceedings of the National Academy of Sciences of the United States of America.

[71]  D. E. Olins,et al.  Nonhistone chromosomal protein HMG 1 interactions with DNA. Fluorescence and thermal denaturation studies. , 1985, The Journal of biological chemistry.

[72]  A. Klug,et al.  Structure of the nucleosome core particle at 7 Å resolution , 1984, Nature.

[73]  L. Kuehl,et al.  Concentrations of high-mobility-group proteins in the nucleus and cytoplasm of several rat tissues , 1984, The Journal of cell biology.

[74]  J. Palau,et al.  Interaction between domains in chromosomal protein HMG‐1. , 1984, The EMBO journal.

[75]  F. Harper,et al.  Rat liver HMG1: a physiological nucleosome assembly factor. , 1984, The EMBO journal.

[76]  Hen-Ming Wu,et al.  The locus of sequence-directed and protein-induced DNA bending , 1984, Nature.

[77]  A. Kornberg,et al.  Protein HU in the enzymatic replication of the chromosomal origin of Escherichia coli. , 1984, Proceedings of the National Academy of Sciences of the United States of America.

[78]  J. Palau,et al.  DNA and histone H1 interact with different domains of HMG 1 and 2 proteins. , 1983, The EMBO journal.

[79]  R. Roeder,et al.  Eukaryotic gene transcription with purified components. , 1983, Methods in enzymology.

[80]  G. Reeck,et al.  Domain structure in high molecular weight high mobility group nonhistone chromatin proteins , 1982, Nature.

[81]  W. Marzluff,et al.  HMG-proteins 1 and 2 are required for transcription of chromatin by endogenous RNA polymerase. , 1982, Biochemical and biophysical research communications.

[82]  G. Reeck,et al.  Influence of nonhistone chromatin protein HMG-1 on the enzymatic digestion of purified DNA. , 1982, Nucleic acids research.

[83]  E. W. Johns.  The HMG chromosomal proteins , 1982 .

[84]  R. L. Baldwin,et al.  DNA flexibility studied by covalent closure of short fragments into circles. , 1981, Proceedings of the National Academy of Sciences of the United States of America.

[85]  M. Yaniv,et al.  E. coli DNA binding protein HU forms nucleosome-like structure with circular double-stranded DNA , 1979, Cell.

[86]  G. Goodwin,et al.  Interaction of a non-histone chromatin protein (high-mobility group protein 2) with DNA. , 1975, European journal of biochemistry.

[87]  G. Goodwin,et al.  Interactions of a purified non-histone chromosomal protein with DNA and histone. , 1974, European journal of biochemistry.

[88]  G. Goodwin,et al.  A new group of chromatin-associated proteins with a high content of acidic and basic amino acids. , 1973, European journal of biochemistry.