PMID- 10644686
OWN - NLM
STAT- MEDLINE
DCOM- 20000229
LR  - 20190508
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 275
IP  - 4
DP  - 2000 Jan 28
TI  - Cloning, expression, and functional characterization of the beta regulatory
      subunit of human methionine adenosyltransferase (MAT II).
PG  - 2359-66
AB  - MAT II, the extrahepatic form of methionine adenosyltransferase (MAT), consists
      of catalytic alpha(2)/alpha(2') subunits and a noncatalytic beta subunit,
      believed to have a regulatory function. The full-length cDNA that encodes the
      beta subunit of human MAT II was cloned and found to encode for a 334-amino acid 
      protein with a calculated molecular weight of 37,552. Analysis of sequence
      homology showed similarity with bacterial enzymes that catalyze the reduction of 
      TDP-linked sugars. The beta subunit cDNA was cloned into the pQE-30 expression
      vector, and the recombinant His tagged protein, which was expressed in
      Escherichia coli, was recognized by antibodies to the human MAT II, to synthetic 
      peptides copying the sequence of native beta subunit protein, and to the rbeta
      protein. There is no cross-reactivity between the MAT II alpha(2) or beta
      subunits. None of the anti-beta subunit antibodies reacted with protein extracts 
      of E. coli host cells, suggesting that these bacteria have no beta subunit
      protein. Interestingly, the rbeta subunit associated with E. coli as well as
      human MAT alpha subunits. This association changed the kinetic properties of both
      enzymes and lowered the K(m) of MAT for L-methionine. Together, the data show
      that we have cloned and expressed the human MAT II beta subunit and confirmed its
      long suspected regulatory function. This knowledge affords a molecular means by
      which MAT activity and consequently the levels of AdoMet may be modulated in
      mammalian cells.
FAU - LeGros, H L Jr
AU  - LeGros HL Jr
AD  - Veterans Affairs Medical Center, Memphis, Tennessee 38104, USA.
FAU - Halim, A B
AU  - Halim AB
FAU - Geller, A M
AU  - Geller AM
FAU - Kotb, M
AU  - Kotb M
LA  - eng
SI  - GENBANK/AF182814
GR  - GM-54892-09/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (DNA, Complementary)
RN  - EC 2.5.1.6 (Methionine Adenosyltransferase)
SB  - IM
MH  - Amino Acid Sequence
MH  - Base Sequence
MH  - Cloning, Molecular
MH  - DNA, Complementary
MH  - Escherichia coli/genetics
MH  - Humans
MH  - Methionine Adenosyltransferase/chemistry/*genetics
MH  - Molecular Sequence Data
MH  - Sequence Homology, Amino Acid
EDAT- 2000/01/25 09:00
MHDA- 2000/03/04 09:00
CRDT- 2000/01/25 09:00
PHST- 2000/01/25 09:00 [pubmed]
PHST- 2000/03/04 09:00 [medline]
PHST- 2000/01/25 09:00 [entrez]
AID - 10.1074/jbc.275.4.2359 [doi]
PST - ppublish
SO  - J Biol Chem. 2000 Jan 28;275(4):2359-66. doi: 10.1074/jbc.275.4.2359.