AHM1, a novel type of nuclear matrix-localized, MAR binding protein with a single AT hook and a J domain-homologous region.
Interactions between the nuclear matrix and special regions of chromosomal DNA called matrix attachment regions (MARs) have been implicated in various nuclear functions. We have identified a novel protein from wheat, AT hook-containing MAR binding protein1 (AHM1), that binds preferentially to MARs. A multidomain protein, AHM1 has the special combination of a J domain-homologous region and a Zn finger-like motif (a J-Z array) and an AT hook. For MAR binding, the AT hook at the C terminus was essential, and an internal portion containing the Zn finger-like motif was additionally required in vivo. AHM1 was found in the nuclear matrix fraction and was localized in the nucleoplasm. AHM1 fused to green fluorescent protein had a speckled distribution pattern inside the nucleus. AHM1 is most likely a nuclear matrix component that functions between intranuclear framework and MARs. J-Z arrays can be found in a group of (hypothetical) proteins in plants, which may share some functions, presumably to recruit specific Hsp70 partners as co-chaperones.
Morisawa
G
G
Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Han-Yama
A
A
Moda
I
I
Tamai
A
A
Iwabuchi
M
M
Meshi
T
T
D000595:Amino Acid Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli; D036961:Matrix Attachment Region Binding Proteins; D008969:Molecular Sequence Data; D015530:Nuclear Matrix / Q000378:metabolism*; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011089:Polydeoxyribonucleotides / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014908:Triticum / Q000235:genetics / Q000378:metabolism*; D016335:Zinc Fingers
C417769:AHM1 protein, Triticum aestivum; D004268:DNA-Binding Proteins; D036961:Matrix Attachment Region Binding Proteins; D009687:Nuclear Proteins; D010940:Plant Proteins; D011089:Polydeoxyribonucleotides; D011994:Recombinant Proteins