The term was introduced by Chetverin[1] to make nomenclature in the Na/K-ATPaseenzyme unambiguous. This enzyme is composed of two subunits: a large, catalytic α subunit, and a smaller glycoprotein β subunit (plus a proteolipid, called γ-subunit). At the time it was unclear how many of each work together. In addition, when people spoke of a dimer, it was unclear whether they were referring to αβ or to (αβ)2. Chetverin suggested to call αβ a protomer and (αβ)2 a diprotomer. Thus, in the work by Chetverin the term protomer was only applied to a hetero-oligomer and subsequently used mainly in the context of hetero-oligomers. Following this usage, a protomer consists of a least two different proteins chains. In current literature of structural biology, the term is commonly also applied to the smallest unit of homo-oligomers, avoiding the term "monomer".
In chemistry, a so-called protomer is a molecule which displays tautomerism due to position of a proton.[2][3]
Examplesedit
Hemoglobin is a heterotetramer consisting of four subunits (two α and two β). However, structurally and functionally hemoglobin is described better as (αβ)2, so we call it a dimer of two αβ-protomers, that is, a diprotomer.[4]
Examples in chemistry include tyrosine and 4-aminobenzoic acid. The former may be deprotonated to form the carboxylate and phenoxide anions,[5] and the later may be protonated at the amino or carboxyl groups.[6]
Referencesedit
^Chetverin, A.B. (1986). "Evidence for a diprotomeric structure of Na, K-ATPase: Accurate determination of protein concentration and quantitative end-group analysis". FEBS Lett. 196 (1): 121–125. doi:10.1016/0014-5793(86)80225-3. PMID 3002859.
^P. M. Lalli, B. A. Iglesias, H. E. Toma, G. F. de Sa, R. J. Daroda, J. C. Silva Filho, J. E. Szulejko, K. Araki and M. N. Eberlin, J. Mass Spectrom., 2012, 47, 712–719.
^C. Lapthorn, T. J. Dines, B. Z. Chowdhry, G. L. Perkins and F. S. Pullen, Rapid Commun. Mass Spectrom., 2013, 27, 2399–2410.
^Buxbaum, E. (2007). Fundamentals of protein structure and function. New York: Springer. pp. 105–120. ISBN978-0-387-26352-6.
protomer, confused, with, promoter, structural, biology, protomer, structural, unit, oligomeric, protein, smallest, unit, composed, least, protein, chain, protomers, associate, form, larger, oligomer, more, copies, this, unit, usually, arrange, cyclic, symmetr. Not to be confused with Promoter In structural biology a protomer is the structural unit of an oligomeric protein It is the smallest unit composed of at least one protein chain The protomers associate to form a larger oligomer of two or more copies of this unit Protomers usually arrange in cyclic symmetry to form closed point group symmetries The term was introduced by Chetverin 1 to make nomenclature in the Na K ATPase enzyme unambiguous This enzyme is composed of two subunits a large catalytic a subunit and a smaller glycoprotein b subunit plus a proteolipid called g subunit At the time it was unclear how many of each work together In addition when people spoke of a dimer it was unclear whether they were referring to ab or to ab 2 Chetverin suggested to call ab a protomer and ab 2 a diprotomer Thus in the work by Chetverin the term protomer was only applied to a hetero oligomer and subsequently used mainly in the context of hetero oligomers Following this usage a protomer consists of a least two different proteins chains In current literature of structural biology the term is commonly also applied to the smallest unit of homo oligomers avoiding the term monomer In chemistry a so called protomer is a molecule which displays tautomerism due to position of a proton 2 3 Examples editHemoglobin is a heterotetramer consisting of four subunits two a and two b However structurally and functionally hemoglobin is described better as ab 2 so we call it a dimer of two ab protomers that is a diprotomer 4 Aspartate carbamoyltransferase has a a6b6 subunit composition The six ab protomers are arranged in D3 symmetry Viral capsids are usually composed of protomers HIV 1 protease forms a homodimer consisting of two protomers Examples in chemistry include tyrosine and 4 aminobenzoic acid The former may be deprotonated to form the carboxylate and phenoxide anions 5 and the later may be protonated at the amino or carboxyl groups 6 References edit Chetverin A B 1986 Evidence for a diprotomeric structure of Na K ATPase Accurate determination of protein concentration and quantitative end group analysis FEBS Lett 196 1 121 125 doi 10 1016 0014 5793 86 80225 3 PMID 3002859 P M Lalli B A Iglesias H E Toma G F de Sa R J Daroda J C Silva Filho J E Szulejko K Araki and M N Eberlin J Mass Spectrom 2012 47 712 719 C Lapthorn T J Dines B Z Chowdhry G L Perkins and F S Pullen Rapid Commun Mass Spectrom 2013 27 2399 2410 Buxbaum E 2007 Fundamentals of protein structure and function New York Springer pp 105 120 ISBN 978 0 387 26352 6 J Am Chem Soc 2009 131 3 pp 1174 1181 J Phys Chem A 2011 115 26 pp 7625 7632External links edit nbsp Look up protomer in Wiktionary the free dictionary nbsp This enzyme related article is a stub You can help Wikipedia by expanding it vte nbsp This biophysics related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Protomer amp oldid 1220899087, wikipedia, wiki, book, books, library,
