Hell¡¯s Gate globin I: An acid and thermostable bacterial hemoglobin resembling mammalian neuroglobin

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• 作者：Aik-Hong  ; Teh^a ; Jennifer A.  ; Saito^a ; Aida  ; Baharuddin^a ;   ; ¹ ; Jason R.  ; Tuckerman^b ; James S.  ; Newhouse^c ; Masaomi  ; Kanbe^a ; Elizabeth I.  ; Newhouse^c ; Rashidah Abdul  ; Rahim^a ; Fré ; dé ; rique  ; Favier^d ; Claude  ; Didierjean^d ; Eduardo H.S.  ; Sousa^e ; Matthew B.  ; Stott^f ; Peter F.  ; Dunfield^g ; Gonzalo  ; Gonzalez^b ; Marie-Alda  ; Gilles-Gonzalez^b ; Nazalan  ; Najimudin^a ; Maqsudul  ; Alam^a ;   ; ^h ;   ; ⁱ ;   ; ^{alam@hawaii.edu} ;   ; ^{maqsudul@ccbusm.edu.my}
• 关键词：Hell&rsquo ; s Gate globin I ; Globin ; Crystal structure ; Oxidation resistance ; Molecular dynamics ; Oxygen binding
• 刊名：FEBS Letters
• 出版年：2011
• 出版时间：20 October 2011
• 年：2011
• 卷：585
• 期：20
• 页码：3250-3258
• 全文大小：1705 K

文摘

Hell¡¯s Gate globin I (HGbI), a heme-containing protein structurally homologous to mammalian neuroglobins, has been identified from an acidophilic and thermophilic obligate methanotroph, Methylacidiphilum infernorum. HGbI has very high affinity for O₂ and shows barely detectable autoxidation in the pH range of 5.2?.6 and temperature range of 25?0 ¡ãC. Examination of the heme pocket by X-ray crystallography and molecular dynamics showed that conformational movements of Tyr29(B10) and Gln50(E7), as well as structural flexibility of the GH loop and H-helix, may play a role in modulating its ligand binding behavior. Bacterial HGbI¡¯s unique resistance to the sort of extreme acidity that would extract heme from any other hemoglobin makes it an ideal candidate for comparative structure¨Cfunction studies of the expanding globin superfamily.