*Article* **Possible Transmission Flow of SARS-CoV-2 Based on ACE2 Features**

**Sk. Sarif Hassan <sup>1</sup> , Shinjini Ghosh <sup>2</sup> , Diksha Attrish <sup>3</sup> , Pabitra Pal Choudhury <sup>4</sup> , Alaa A. A. Aljabali <sup>5</sup> , Bruce D. Uhal <sup>6</sup> , Kenneth Lundstrom <sup>7</sup> , Nima Rezaei 8,9 , Vladimir N. Uversky 10,\* , Murat Seyran <sup>11</sup>, Damiano Pizzol <sup>12</sup> , Parise Adadi <sup>13</sup> , Antonio Soares <sup>14</sup>, Tarek Mohamed Abd El-Aziz 14,15 , Ramesh Kandimalla 16,17 , Murtaza M. Tambuwala <sup>18</sup> , Gajendra Kumar Azad <sup>19</sup> , Samendra P. Sherchan <sup>20</sup> , Wagner Baetas-da-Cruz <sup>21</sup>, Kazuo Takayama <sup>22</sup> , Ángel Serrano-Aroca <sup>23</sup> , Gaurav Chauhan <sup>24</sup>, Giorgio Palu <sup>25</sup> and Adam M. Brufsky <sup>26</sup>**


Received: 4 November 2020; Accepted: 10 December 2020; Published: 13 December 2020 -

**Abstract:** Angiotensin-converting enzyme 2 (ACE2) is the cellular receptor for the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that is engendering the severe coronavirus disease 2019 (COVID-19) pandemic. The spike (S) protein receptor-binding domain (RBD) of SARS-CoV-2 binds to the three sub-domains viz. amino acids (aa) 22–42, aa 79–84, and aa 330–393 of ACE2 on human cells to initiate entry. It was reported earlier that the receptor utilization capacity of ACE2 proteins from different species, such as cats, chimpanzees, dogs, and cattle, are different. A comprehensive analysis of ACE2 receptors of nineteen species was carried out in this study, and the findings propose a possible SARS-CoV-2 transmission flow across these nineteen species.

**Keywords:** ACE2; viral spike receptor-binding domain; SARS-CoV-2; transmission; bioinformatics
